Any private key is actually an integer between 0 and 2²⁵⁶ and is converted to other formats like WIF. (That's for making the copy-pasting easier and decreasing the chance of mistakes with including a checksum).

Of course,  not any integer between 0 and 2²⁵⁶ can be a valid private key. Due to secp256k1 ECDSA standard, the number of valid private keys is a bit smaller.

P2SH-P2PK addresses:
I don't recommend using P2SH-P2PK addresses. Because Armory uses it own algorithm for generating these addresses and you will always rely on Armory for spending from these addresses.
Please someone correct me, if there's any other wallet allowing users to spend from P2SH-P2PK addresses


P2SH-P2WPKH addresses:
I would prefer P2SH-P2WPKH addresses over legacy addresses. They are called nested segwit addresses and you will pay a lower transaction fee comparing to legacy addresses.
Unlike P2SH-P2PK addresses and like legacy addresses, these addresses can be exported from Armory and imported to many other wallets.


Note that there's another type of bitcoin address called native segwit. They are also called as bech 32 or p2wpkh addresses.
Using these addresses, you would pay a lower fee even compared to nested segwit addresses, but they are not supported by Armory.

For every transaction you make, you need the private key of your address to sign the transaction.
When you make a transaction, your seed phrase isn't directly used for signing the transaction. Your seed phrase (which is a series of words) is used to create a seed. Then the seed is used for generating the extended private key and the extended private key is used for generating your private key(s).
So, Any seed phrase gives you access to numerous addresses. But a private key gives you access to one address only (of course, more addresses if different script types are considered)

It should be noted that your private key(s) can be derived from your seed phrase. But your seed phrase can't be derived from your private key(s).

What is the version of Armory you are using for your watch-only wallet?
I think everything should be fine if you use the latest version of Armory which is 0.96.5.

In the case you are not using the latest version of Armory, download it from the official website.

Transactions are prioritized based on the fee paid per vbyte, not byte.
vbyte is a unit for measurement of virtual size of transactions.
In the case you use segwit address(es), the virtual size of your transaction will be smaller and the required fee would be lower.

Anyway, I also recommend you to use mempool.space. That's very helpful especially for newbies. But if you want to see a very accurate graph showing the mempool state, you can use jochen-hoenicke website. It allows you to analyse the mempool yourself.

The fee you need to pay for a transaction doesn't depend on the sending amount.

The transaction fee depends on:
1. Number of inputs and outputs
2. The network state (how busy the network is)
3. How fast you want your transaction to be confirmed
4. Your addresses type (legacy, nested segwit or native segwit)

Change is the remaining balance of the UTXOs picked for the tranasction.

Assuming you sent 0.5 BTC to 3Mnr2U........, 39EeRH........... should be your change address.
If you make a transaction from your change address with an enough high fee, miners will include both transactions (the main transaction and the one made from your change address) in a same block.
(This method is called CPFP.)

Anyway, I recommend you to bump the fee using electrum (as suggested by LoyceV). It should be cheaper than CPFP.  

As far as I know, exodus isn't open source. Both desktop and mobile versions are close source.
I have used exodus before (only for holding some altcoins in short term) and honestly never experienced any problem. Also, I haven't ever heard of any security issue with exodus till now. But since it's close source, I still wouldn't trust it, especially for long-term holding.

For ethereum, you can also try metamask.

For ethereum, you need to use another wallet.
The best is to buy a hardware wallet like Trezor. It's open source and can provide the maximum security.

There are also many multi-currencies wallets. But the problem is they are close source.


Technically, it's possible to force electrum to do so. But since that's not a standard seed phrase and you won't be able to generate a same wallet using other wallets, that's not recommended at all.
If you want to have a valid seed phrase with your selected words, you must select 11 words from BIP39 wordlist and brute-force the 12th word.
Of course, it's not a recommended method and you should let the seed phrase to be generated by electrum. Humans are not good at generating random data.


For ethereum I don't think there's any.
Again, it's not recommended to have a seed phrase with your selected words, even if it's possible.

Enable deposits? Or enable withdrawals?
Any service asking you to make a deposit to be able to make a withdrawal is 99.9999% scam.

Don't send any document to them and don't waste more money making another deposit.
The only thing you can do now is to learn the lesson.

In an electrum's seed phrase, all words (all 132 bits) are generated randomly.
Electrum's seed doesn't have a checksum same as a BIP39 seed in which the last 4 bits are checksum.
Electrum only checks the first 8 bits of the hash of the seed phrase to see if it can be a valid seed phrase.

No.
It's not that the seed phrase is generated by a third party and is given to you.

Any seed phrase is only a representative of a large random number.
For generating the seed phrase from that random number (which can be generated by your operating system), you need to use a tool like electrum. You can even do it yourself, if you have enough mathematical skills.
Electrum doesn't do anything more than this when creating a wallet and doesn't have to be online.
All the process of generating the seed phrase can be done offline and developers don't have any control over your seed phrase, your wallet file, your transactions, etc.

It depends on what you want from a wallet.
If you want to run your full node for any reason (like helping the network, having more privacy, etc.), you should use bitcoin core and download the whole blockchain.
(For more information regarding advantages of running a full node, I recommend you to visit bitcoin wiki).

If you don't want to run your full node, you can use SPV wallets like electrum.
In SPV wallets, you don't have to download the blockchain.

Note that electrum or any other SPV wallet can't provide as much privacy and security as bitcoin core do.

Exactly.
For example, when you use electrum, you can be sure that you are the only one who has access to the seed phrase. (Of course, there's still the chance of getting hacked, if you generate the wallet or store the wallet file on an online computer).

A good example showing why you shouldn't trust close-source wallets is coinomi.  
They were sending users seed phrase to google servers. (Click here to see how the vulnerability caused a user to lose his fund)
Coinomi has solved the issue, but we still can't be sure that users seed phrases aren't stored on any server. This applies to all other close-source wallets as well.

Custodial wallets work in a completely different way than a HD wallet. So when it comes to a custodial wallet, there is no seed phrase at all it doesn't make sense to say where the seed phrase is stored.
Whenever you send a fund to a custodial wallet or an exchange, you actually send the fund to an address owned by them, not your own (HD) wallet.

There are two different coinbase wallets. One of them is custodial and the other one is non-custodial.
In the case of using coinbase custodial wallet, you are right. You won't have any seed phrase. But in the case you use their non-custodial wallet, it gives you the seed phrase.

You can't send any merit. Because you don't have any smerit.
For more information, visit the link below.
Merit & new rank requirements


Since the wallet in question is close-source, there is no way to know whether the seed phrase is stored on their server or not.
For more security, you need to use an open-source wallet.

You are probably talking about swapping tokens on decentralized exchanges like Uniswap and Pancakeswap?

The fee you have to pay is the sum of the transaction fee and trading fee.

Trading fee is a percentage of the trade volume and shouldn't be high. (It's usually between 0.1% and 0.3%.
The transaction fee depends on the network state.

If you use ERC20 USDT or any other token on ethreum network, you will have to pay a very high fee. (It should be at least 50 dollars at the current rates, if I am not wrong.)
If you use BNB or any BEP20 tokens on binance smart chain, the required transaction fee would be much lower.

I haven't ever mined any altcoin and I don't have much information about it. But I think whattomine can be helpful to you. You can use it to calculate profitability of mining different cryptocurrencies.

You should either have a high-performance GPU (Graphics processing unit) or buy an ASIC miner.

Email address changes are not reported on BPIP at all. Therefore, there's still the possibility that the user's email address has been changed.
Email address changes are only reported on user's trust summary page and the message saying that disappears after 30 days.