So you prefer versatility and resale value than shorter ROI.

If you're into GPU, choose Nvidia, but not the not-so-latest releases like the RTX series.
The best possible candidates are GTX 1070(ti) or 1080(ti) for maximum compatibility to both mining software and algos.
You'll likely find it harder to configure for RTX series GPU than GTX ones and the current price can't even justify the low difference in the hashrates of GTX GPUs.

Also, you can find dozens of secondhand GTX1070s and 80's in online/local stores (brand new ones are cheaper now as well).

Obviously, aside from it just started last year, miners realized that it's more profitable than Ethereum because of "whattomine" or other sites and collectively switched to RVN.

It's as simple as this: More miners = higher difficulty.

Usually, the 1st bonus will be applied the same time as the "no capcha" bonus (about an hour or two).
You can check it in the "REQUIREMENTS TO UNLOCK BONUSES" and click "PLAY FREE BTC WITHOUT CAPTCHA".

So far, I've only reached the third bonus through my Hi/Lo winning endeavor.

But take note, the third bonus depleted too fast (just 10-20 free claims) and fell to the second tier bonus.

How can your rig only consume 750W?
Each card has TDP of 120W which could reach up to 180W of power in real usage.
Also the processor, motherboard, Drives and peripherals consumes power, even with 120W the whole rig would consume more than 750W.

You might be losing more than you think, how much is your electricity cost?

"Free Electricity" Dudes.
Huge Mining farms with low-cost Electricity or additional alternative sources (Ex. Solar).

16, 17 or 19 words can't be a SEED unless the excess words are customized extensions like Electrum implemented.
But still, you said that "these words" aren't belong to BIP39 word list (really, all of them?); It's not a SEED then.

There's only one Bitcoin-related wallet generator I know (address & private key pair) that can make use of any word and any number of words: Brainwallet.
It's pretty popular during that time, you might have created a brainwallet and imported the private key/address to blockchain.info before.

Does Brainwallet ring a bell?

Everything's pretty much answered so I'll just add this:

Display the "Coins" Tab by clicking "View->Show Coins"; in that tab, all of your available UTXOs will be displayed.
If you found too many small values like 0.00001BTC or below, either [1] freeze them temporarily and consolidate them once the average fee falls to low value again or [2] Always manually select the input(s) in every transaction and refrain from using more than two inputs.

That's all to save transaction fee which could solve the "insufficient funds" issue by excluding the small inputs that have lower balance than the added fee caused by the additional bytes by including them.

@asriloni I've read the article you linked and it turns out that the author himself was the one who'd been done the mining like OP wanted.

Well, the issue is about "security" not a breach to their policy.
Worst case scenario (if mining is prohibited) is his Azure account will be suspended or banned but it's free and almost expired anyways.

Why Paper wallets in general though?
You can suggest them to create their own paper wallet using other means, manual or by other offline tools. It's not too "techie".

Example:

• Create a wallet using Electrum on an AirGapped (offline) PC
• Export 1 private key address pair.
• Copy it to a piece of paper (Try to restore a new wallet using the private key for verification)
• Delete the Wallet, low-level format the PC or crush the hard drive (for paranoids) after.

Just check his profile and click "Show the last topics started by this person." and from there, his latest threads will appear.

And luckily, the latest is the one that you're looking for: BlackMiner F1mini Review (Incomplete)

Those tools are useless for hard drives with its "Master Boot Record" all zeroed, ETFbitcoin described his term "full format" like "Zero Fill", so he really meant zero fill.
It's also known as "Low level formatting".

This will work.
And in my own experience, it delivers better cooling than the stock fans (at least for my cheap brand GPUs).

---

@Harai Goshi Though I'm puzzled with your "fan cost problem", maybe you're talking about the whole HeatSink (Metal Part under the fan) and Fan for the GPU?
The fan alone should be cheap ($20±) and wont cost you more than a quarter of the whole GPU.

I won't answer the questions directly but this should help you understand "Bitcoin" and hopefully answer those questions yourself.

• Bitcoins aren't stored in the wallets, it's stored in the full nodes bundled as "blocks".
• The only way to spend it is to have the proper private key for the addresses.
• Set of private keys can be derived from the SEED (or other forms) for HD (Hierarchical Deterministic) wallets, but some wallets just use random private keys.
• The Wallets (hardware or not) either contains the SEED or just random private keys. With that, it can communicate to the network to check if the private key's paired address have UTXO (unspent outputs) that can be totaled as balance.

You've lots of hardware wallet-related questions, I guess you're concerned about its security?
∙ Basically, if your Hardware Wallet have a strong Passphrase and a PIN, it's unhackable even if they got your wallet physically.
∙ The only thing that a hacker/thief needs to steal your Bitcoins are your SEED (whole wallet) or your private keys (per address).

It will also depend on how "non-standard" the transaction is.

If it is something like a 0sat/byte tx fee transaction, that's possible and they might agree to include it.
But if it is is trying to spend from old lost inputs with forged signatures, that's impossible as the block will surely get rejected by other nodes.

BTW, kano pool's owner is very active, send him a PM.

This is kinda bad for your security.
What is the main reason for you to entrust the SEED to someone else? On top of that, you never had your own backup of the SEED until yesterday.

He still got your SEED and he can spend your coin whenever he wants.

It will be sent to the mainnet address and if you didn't have the Private key for that address, it will be lost.
The problem is the format, usually, testnet and mainnet wallet are different and you wont be able to send mainnet coins to testnet address (don't know about shift).

But as I said above:
If your wallet displays the same set of addresses for the testnet and mannet wallet (given that it uses the same SEED), you might be able to recover it by opening the wallet as "mainnet".

Can you tell us the first three character of your testnet shift address and a sample of mainnet shift address?

You can try it.
BTW, it's not a passphrase, it's the SEED where all the wallet addresses' private keys are based from.

For comparison: if it was Bitcoin, the testnet address and the mainnet address should be different and start with "2" and "1" respectively;
and testnet addresses will be rejected by the Exchange.

Don't get your hopes up but,
since your testnet Shift wallet address was accepted by the exchange, chances that it uses the same address for the mainnet is high (and it uses the same SEED). If you selected "mainnet" to the drop-down menu, just check the address list (if any) if it displays the same set of addresses as the testnet wallet.
If the addresses are the same, the problem could be something else.

If you get positive result from the above paragraph: what wallet was it? Some sort of a full node or a SPV (light) client?
If it is a full node (select mainnet), you might need to sync it first to properly display your balance (it may require a lot of storage space depending on the Coin/Network).
For light clients, it might be a connection issue.

Lol, I though no one will notice.
Just FYI, the only "Satoshi" from an anime I know has a surname "Tajiri" while our Satoshi might meant more than just a Japanese pseudo-name.
Satoshi means "Intelligent" and Nakamoto means "Central Origin".
Bitcoin was created during the world fame of that anime though (10+ years after the release in Japan), pff... coincidence.

And this is theymos: Toushou_Daimos (Daimos)

What version of Electrum are you using? If it is older than v3.3.3, refrain from following messages from the client.
Also, if you downloaded it somewhere else other than electrum.org, do not use it it might be trying to hack your SEED via social engineering tactics.

Here's to restore from SEED:

• Go to electrum.org and download the latest version.
• Open/Install it and Create a new wallet by selecting Standard Wallet->I already have a SEED.
• Paste your 12-word SEED there and continue.
• After restoring the wallet, click the receive tab and check if the address is familiar.

Can you recall the original addresses? Do they start with "1", "3" or "bc1"?

Also, you said you've tried to enable the "BIP39" option, right?
If it happened to be a BIP39 SEED, was the message on the left side of the option said "BIP39 (checksum: failed)" or "BIP39 (checksum: ok)"?
Because any of the two will enable you to press "next" button to create the wallet but real BIP39 SEED will display as "ok".
If not, you might have miss-clicked one or changed the order (now or during the 1st wallet creation backup).

It's useless then, Electrum complies with backward compatibility with the SEED (not BIP39 SEEDs) and it's pretty much the same with the newer versions.
That's only an option if you still have the original wallet file.

Quoted and Verified via Brainwallet.

It's a legacy address, we don't have to use Electrum to verify it.