No, it's not a good chance... In fact, i've been in this community for many, many years, and i can tell from experience that the odds of this site being legit are in fact incredibly small... In my years i've never seen a site that asks for a deposit in order to activate a withdrawal being legit in the end. From time to time, they turn out to be ponzi's and early investors get their money, but in the end the late investors always get scammed.

The thing is: you're not taking any risks, since you don't offer any collateral. So if the site turns out to be a scam (and there's a big chance it is) you can just walk away and it's the person giving you a loan that carries all the risk (not you).

99,99% of the websites that force you to deposit money in order to activate the withdrawal of money are in fact scams.

Since you offer no collateral whatsoever, only 2 things can happen if somebody would lend you the 0.02 btc you request:

1 => there's a big chance you'll send the 0.02 btc you've lent to this site, they scam you, you run away, the lender is out of 0.02 btc and never hears from you again
2 => there's a really, realy, really, really, really small chance you send the 0.02 BTC to the site, get scammed and refund the lender with your own money... In this case it's you that got scammed and not the lender

Neither of these options is good...

BTW: this forum uses the no collateral =  no loan rule... People that don't follow this rule usually get red tagged to warn other members about their behavior

https://github.com/greenaddress/abcore

if you run this one in pruned mode, you have your exact answer...

Altough, i'd recommand not to run a full node on an android phone... Like NeuroticFish already said: go for an SPV wallet instead (many of those are available)

Agreed... 0.0005 is 9 satoshi's, making this option better than claiming from faucets (last time i had a discussion with somebody about faucets, i think the average payout was less than 50 satoshi's, but in order to claim one had to visit 3 or 4 pages, filling in different sorts of captcha's, and in a big percentage of the cases the faucet was either a scam or dry)...

I had the opinion that one should get an IRL job and buy BTC with part of their wage instead of using faucets, but some other (senior) members did make a valid point when they told me that in some countries there are no "minimum wage jobs" paying $9/hour.. And those people claiming from faucets actually make more money than if they'd search for a regular job in those thirth world countrys, this included their hardware, internet and electricity. Sad but true.

I can setup a wordpress website if you have suitable hosting available (either shared hosting offering php and mysql, or a VPS with a LAMP stack)... I have some time tomorrow morning.

I'll only do this if we use a reputable escrow or if i'm payed beforehand, and i don't provide support using wordpress, installing extra plugins, troubleshooting misusage,... I'll just leave you with a clean install when i'm done, from then on it's up to you.

PM me if you're interested (i prefer to keep things on this forum, i don't use discord or telegram anyways)

One of the key concepts of bitcoin and allmost all other altcoins is immutability. This basically means that if your transaction is valid and included in a valid block that has been broadcasted and accepted by most nodes of the network, the transaction becomes irreversible. This is certainly the case once a couple valid of blocks have been found and added to the blockchain after the block including the transaction the thief generated to rob you.

This is why i don't fully agree with your OP: if you monitor your coins, you don't gain a lot of security... As soon as somebody steals from you, your funds are gone wether you monitored them or not...

The only difference between monitoring and not monitoring might be that if you monitor, and for some reason you have used the same xprv or private key on multiple chains, you might be able to saveguard unspent outputs on different chains before the attacker is able to spend them... This *might* be the case for those forked chains, or for multi-coin wallets.

I do agree with your final comment: never store your coins on exchanges, casino wallets, online wallets,...

This is just my personal opinion, but i'd answer your question as: Yes, the lightning network is up and running

1) the clients are becoming reasonable... As a gui client i use Eclair mobile, and eventough it has a learning curve, it's reasonable (at least, that's my opinion)
2) you are referring to the fee you have to pay for the on-chain transaction used for opening and closing transactions... Yes, this fee can be more than a "regular" on-chain transaction, since a lot of "regular" wallets allow you to cheap out on fees (they have an "economy" setting  that actually underestimates the needed fee... While most lightning network wallets usually seem to pay the optimal fee without leaving you the option to cheap out). However, once a channel has been openened, the fees are really small (at least, they've been small for all the payments i made).

The lightning network is still in an early stage, and it'll never be as safe as an on-chain transaction... But at the moment i consider is usable, the learning curve seems reasonable to me, there are a couple of reasonably good wallets,...

I don't mean to sound like a jerk, but I have re-read this post at least 5 times and it still makes no sense...

Is it a google translate issue, or are you just making things up?

I'm a fan of the lightning network, but it's meant for smaller payments, and is less safe than an on-chain transaction... So there'll always be a place for altcoins like litecoin or dash... Altough they might lose some of their marketshare due to the LN.

Just my opinion based on running a lightning-enabled website for a "long" time (at least, a long time in the lightning network existance timeframe).

Basically, like the article said: if i was selling a second hand DVD, i'd prefer being payed with a LN invoice, if i was selling my car and i wanted fast confirmations, i'd accept LTC

Well, somebody doublespending the unspent outputs used as an input for a transaction is ALWAYS a possibility, as long as the transaction has 0 confirmations (the odds get very low after 1 confirmation since it would require a fork of the chain after 1 confirmation). This isn't a new problem since rbf was introduced...
 
If you're selling something cheap, you might not care and accept 0 conf transactions anyways, just to increase the shopping experience of your honest customers... I mean, i consider falling victim to a double spend about the same as getting payed with fake money or being the victim of shoplifting. It's a crime, and most people won't try to doublespend. The few people that do can probably be prosecuted, so it might be fine as long as you're not selling expensive goods.

If you're selling something expensive, it might be a good idear to wait  untill the funding tx has at least 2-3 confirmations.

If you can't wait this long, there are alternatives:

• Use an altcoin that has less average time between 2 blocks (with bitcoin, the average time between 2 blocks is ~10 minutes and the blocks are sometimes full so transactions with little fees might not be included in the first couple of blocks... Litecoin has an average time between 2 blocks of ~2.5 minutes, and the odds of these blocks being full is much smaller... So accepting LTC will significantly reduce the time your customer has to wait before his payment is confirmed)
• Use the lightning network. Altough a new customer that doesn't have open channels will still need an on-chain tx to fund a new channel AND the LN is inherently less safe than an on-chain transaction (altough it's much safer than accepting 0 confirmation transactions as valid payment).
• Let your customers open an account and let them fund this account with crypto beforehand. When they purchase goods deduct the amount they have to pay from their account

I agree with Pmalek but wanted to give you some more info...

There are 2 reasons not to re-use addresses. The first one has been discussed by Pmalek. The second one is that as soon as you spend unspent output funding an address, you need to broadcast the public key in the spending transaction. As long as you don't spend any unspent outputs funding an address, nobody knows your public key... Eventough it's not that important, it adds an extra layer of security.

A second thing is that i wanted to point out that a lot of these "problems" of funds being spread over different addresses come from a common misconception: your funds is NOT stored in your wallet. Your wallet contains an xprv from which private keys are derived (this is only the case for HD wallets, non-HD wallets do not contain an xprv, but merely a bunch of private keys). A public key can be derived from your private key, and if the public key is hashed you'll see your address.
Next to this, your wallet might contain some meta info (like labels you added to an address or transaction) and it might keep track of the unspent outputs funding the addresses generated by hashing the public keys belonging to the private keys created by your wallet... Hower, this is merely a caching function, by rescanning the blockchain anybody could find those unspent outputs...
Your funds are not stored in your wallet, they're merely the sum of the output value(s) of one or more of the outputs funding (an) address(es) whose private key(s) you own, that are generated by transactions that are stored on the decentralised blockchain.

So, if you disregard the two main reasons not to re-use your addresses, from a financial AND practical point of view it doesn't really matter if there are 1000 unspent outputs funding 1000 addresses monitored by your wallet, or 1000 unspent outputs funding 1 address monitored by your wallet. If you want to spend part of those 1000 unspent outputs, your wallet will combine them untill the output value funding your addresses are greater or equal to the value with which you want to fund the receiving address + the mining fee... It required no effort from your side, your wallet will take care of keeping track of everything.

Couldn't be a team of Indians... The menu of the qt client doesn't contain the word "sir" not nearly enough... (jk)

When two miners find a new valid blockheader for height x, only one of those blocks can become part of the main chain... The other is orphaned.
If the orphaned block contains other transaction than the block that became part of the main chain, these other transactions will remain unconfirmed untill at least one more block is found and added to the main chain. The transactions that were present in the orphaned block but not in the block on the main chain will still be in the mempool of most mining nodes, so they'll be added to a block later on (unless there's a problem with the transaction, like dust outputs, insufficient fees, improper propagation troughout the network,...)

However, as a "normal" user, you shouldn't worry about this... If you sell something expensive just wait for 2 or 3 confirmations before you send the goods or service.

Foreword
I have been running a full node, c-lightning and lightning-charged for a while now, recently i added a private electrs server and i installed/configured btcpayserver. Since it's quite a task to set all these services up in order to receive lightning payments, there's quite a learning curve, not to mention the hardware requirements and the time needed to set everything up.
I realise the lightning network is still in alpha stage, and at any point it's less secure than an on-chain payment... However it's instant and cheap (once you have open, funded channels), so i wouldn't mind helping people try out accepting lightning payments on my lightning node before going trough the troubles of setting everything up themselfs.

The service
I can setup a useraccount on btcpayserver and install a store for you... That way you'll be able to write lightning invoices for MY lightning wallet. Btcpayserver also allows you to enter your xpub/zpub so it can derive addresses for on-chain payments (altough this is not the focus of this service). Btcpay isn't 100% stable when creating LN invoices tough (the service needs to be restarted manually since it seems to lose connection to my lightning-charged deamon from time to time).
Alternatively, i can work with you to setup a service trough my lightning-charged daemon, it's less user friendly, less fancy, allows less statistics to be made, but seems to be running stably.
After you've created a bunch of lightning invoices (and received a bunch of lightning payments), you can PM to request an on-chain payout of the sum of the payed invoices minus the service fee.

Who can apply for this service
I'm not a commercial entity (altough this service is not free), so my primary focus group are people that receive micro-payments on an occasional basis. I'm thinking about private auctions on this forum, raffles on this forum, tipjars, donation pages,... Commercial websites can apply as long as we're talking about trial runs: if you own a webshop and want to try out btcpay integration to receive a couple dozen payments before installing your own service or migrating to bitpay, i'll accept you to.

What are the guarantees
Like i said: i'm not a commercial entity, so i give NO guarantees whatsoever. You should consider all lightning software to be in alpha phase, i will not reimburse any funds in case something goes wrong. I also take no responsability if you lose your job, wife, house, health,... due to problems with my service...
However, in case you're running something solid and you need basic guarantees, i'd be willing to put some funds into escrow so i can't run away... This being said: it'll be pretty hard for most escrows to prove lightning invoices have been payed, so good agreements have to be made beforehand. I'm unwilling to pay the escrow fee or the transaction fees from/to the escrow tough (those ones have to be payed by you)

How much does it cost?
In a perfect world, this service would be free... However, after receiving a reasonable amount of lightning payments on my site (unblur.ninja), i realised that a most customers open a new channel with my node to test out the lightning network. As soon as those channels close i'll be left with a bunch of very small unspent outputs funding my addresses. I'll be forced to spend a bunch on fees in order to spend those small unspent outputs, and i don't want to pay those fees out of my own pocket, even if it's for the good cause.
This is why, at the moment, i propose following service fee:
I propose to visit https://coinb.in/#fees at the moment you request a withdrawal, at this moment we'll simulate how much fees it would cost me to spend the unspent outputs funding my node because of your invoices. We'll count each invoice as 1 input, 50% 'regular' 50% 'segwit' and add 2 outputs (1 regular, 1 segwit). Then we'll add 50% on top (just in case the fees go up by the time the channels have actually closed). Offcourse, if (after a while) you can more or less prove most payments come from repeat customers that already have open, funded, channels, i'll give you a discount.
I consider the fee to be sufficient for me to break even, maybe even make enough to treat myself to a beer over the weekend... However, you should not treat the fee as a "get rich quick" scheme from my side, it's basically enough to make sure i don't have to fund this service out of my own pocket... So don't expect professional grade support or uptime here!

I agree for 100% with bob123, NeuroticFish and Pmalek, do not store private keys, seeds, xprv's,... on an online machine.

However, i did wanted to add one remark: there seems to be a misconception about hashicorp's vault in your OP: if you're storing the unseal keys or root tokens on your online machine, you're doing it wrong... But i do have to agree that IF you unsealed your vault AND your system gets compromised AND the hacker gets his hands on your machine AND a token (or user/pass or...) he will be able to get your private keys from your server if you were storing them in vault... It's the chicken or the egg dilemma, if you want your scripts to be able to access your private keys directly, a hacker will always have a loophole to do thesame. So your best sollution would be not to store your private keys on an online machine

There are tons of exchanges that had excellent programmers and security audits and strict procedures but still got abused in the end... Don't make the mistake of thinking you're better than those exchanges!

I just added btcpay as a payment backend making it smoother and better looking

Well... I use ubuntu from time to time, but not professionally... A quick google told me that https://ubuntuforums.org/ is the ubuntu support forum where you should be able to find an anwer to your ubuntu related questions...
As for issues with the node setup: bitcointalk's technical subforum => wallet software (https://bitcointalk.org/index.php?board=37.0). This is the subforum that's been started for these issues, altough it's "abused" by people to post their non-core related questions aswell...

There are 3 sollutions to run bitcoind on ubuntu:

• use prebuilt binaries... a tutorial for ubuntu 16.04 can be found here: https://bitcoin.org/en/full-node#ubuntu-1604
• compile bitcoind yourself... a tutorial for ubuntu 16.04 can be found here : https://github.com/bitcoin/bitcoin/blob/master/doc/build-unix.md
• you can download the linux binaries directly: https://bitcoin.org/bin/bitcoin-core-0.17.1/bitcoin-0.17.1-x86_64-linux-gnu.tar.gz

If you want to run bitcoind as a service: https://github.com/bitcoin/bitcoin/blob/master/contrib/init/bitcoind.service

I'm responsible for about 60 x86 servers myself nowadays (my company is moving away from our power architecture towards x86), all my x86 machines are running SLES (everything from 11SP1 till 12SP4), they have tons of good documentation i can access whenever i run into issues. IIRC, ubuntu offers less off the shelve documentation, but they do have good community support forums you can join if you need help. Also, if you post specific, general, questions in this thread, i might be able to point you into the correct direction.

Might i ask which service you're trying to setup? Maybe you're making things to complex? Depending on the virtualisation sollution your VPS provider is offering there might be turnkey sollutions available?

Well... It's kind of hard to give you advice without knowing the specifics of what you're doing...

You have an ubuntu VPS... Sure, but which version (cat /etc/os-release), which VPS provider (digitalocean, ramnode,...), which virtualisation technology (openVZ, XEN,,...), which resources (vCPU's, RAM, disks,...).

Walktroughs seldomly work out-of-the-box unless you follow a walktrough that's tailored to your exact linux distro and version AND the VPS provider you're using... Even then, there are providers that offer openVZ, KVM, Vmware,... virtualisation... There can be a different approach when using ubuntu 18.04 on ramnode's openVZ cluster vs ramnode's KVM cluster...

Bottom line: if you want some advice, it might be good if you told us which exact package from which VPS provider you purchased and which exact OS image you installed on the VM... If not, telling us which error you encounter might also help... But i don't think there's any "general" advice i can give you