No, there's no private key in your default wallet.

That is totally normal for a watching-only wallet.
In the private key menu, there's no "import" option because you cannot add a private key to a wallet with only addresses in it (it is available for imported wallets).
You can only "sweep" because you can still send bitcoins to those imported addresses (but you cannot spend them using that wallet).
'Sweep' sends the pasted private key's entire balance to one of the wallet's address so it's available for all wallet types including watching only.
Lastly, "export" should be grayed-out too because there are no keys in that wallet.

The "named wallet" doesn't display the same transactions so I take that the keys for your default wallet aren't there.

That's a good news if the source of the address isn't an exchange, custodial service or some wallet with undisclosed non-standard derivation path.
Depending on where you got it, you may be able to spend those funds.

One important note when backing up using that method:
Make sure Bitcoin Core isn't running when copying the wallet.dat file because you might backup a corrupted copy (by a low chance).

That guide shouldn't be followed since it's not the correct way to set-up a MultiSig Electrum wallet using hardware devices.
But you already did and here we are.

The users don't need to create a standard wallet in order to get the hardware wallet's xpubs (master public key).
During the creation process, each cosigners should start creating a MultiSig wallet right from the start until the point when they'll be presented with their "Master Public Key".
Then send it to other cosigners (as that cosigner receive theirs) to finish their own MultiSig wallets.

"Descriptor Wallet" is just the new wallet type consisting of 'output descriptors' instead of private keys (aside from the master key),
it's still named 'wallet.dat'.

@SamuelDL  If you set a name for that descriptor wallet and it was created by the later version, the wallet.dat should be in the folder with the same name as that descriptor wallet.
Alternatively, in QT, just use "File->Backup Wallet" while that wallet is selected in the drop-down menu (if multiple wallets are open).

That happens to me most of the time.
After closing Armory-qt, there's always a lingering process of ArmoryDB.exe left in the Task Manager.

Maybe.
There's a chance that Bitcoin Core failed to scan the correct balance and kept the spent inputs in your wallet.
I've seen a couple of topics regarding that, usually those who replaced the wallet.dat file.

BTW, what error did you get when you tried to broadcast the transaction(s) via console?

In case you missed it:
Alternatively, if you want to send them no more: use testmempoolaccept instead.
e.g.:

---

Lastly, if it's just because of the "frequent wallet replacement", rescan might do the trick; open console, select the correct wallet: rescanblockchain

The good thing is, it's only the "UTXO Set" that's corrupted so the possible solution is the faster -reindex-chainstate.

If he'll delete the said file, Bitcoin Core will return with an error and will prompt him to -reindex instead.

There's something that's causing your transactions to get rejected from your own mempool.
There are a few reasons and the most common in not-yet-synced client is if at least one of the input of the transaction is invalid.

You can also try to manually broadcast it and see what mempool-related error you'll get:

• In the transactions tab, right-click on one of the transactions, then select: "Copy raw transaction"
• Open the console (Window->Console), then type: sendrawtransaction "Your_Copied_RAW_Transaction"
• And it should return with an error which should be the reason why those aren't successfully sent.

If it somehow proceed, then there could be in your setting that's preventing txn broadcast..

This only affects compatibility between the raw transactions exported by versions lower than 4.x and the newest.
So, it mainly affects Cold-Storage and MultiSig Electrum wallets that have different versions.

If you're using an outdated wallet for either 1 of the cosigners, update them all fist, then create the transaction.

Yeah, last time I zero-filled a 500GB WD Hard Drive, it took more or less 3 hours if my memory serves me right (that was 3 years ago).
Double that for a 1TB same speed HDD; although, the amount of time is still inconsequential if you want to re-use the disk.

You second~ed the replies yet you've countered their points :/

Anyways, what they meant by "writing 0's" is to 'low-level format' the drives which will turn all of the data on the drive into 0's (binary: 0 or 1).
There's nothing recoverable after that, your example software can only restore deleted files or a formatted drive, those are files which aren't really deleted but flagged as "overwritable".

It means that Armory cannot communicate with Bitcoin Core, you might need to add this to your Bitcoin Core's config file,
bitcoin.conf:

BTW, in that state, you wont be able to broadcast transactions using Armory.

That's problematic and indeed the cause of the corruption as seen in the logs.
My best guess is your Disk is having a hard time keeping up with the I/O, next is your RAM may be full.

When that happens, freeing-up some other processes may unfreeze Bitcoin Core since it should still be running in the background.

I think what you need to do is to find the cause why it's freezing in the first place.
Try to use as little "page file" as possible since Bitcoin Core itself will use lots of HDD processes.
To do that, you'll need to free some RAM space by reducing your background processes or add more RAM.
You can also read this: github.com/bitcoin/bitcoin/blob/master/doc/reduce-memory.md

Lastly, the wallet suggested above is a good alternative if you want to use other clients.

The yellow-highlighted ones are your "Change Addresses", those are addresses reserved to receive the change of your transactions.
Those will not appear in your 'receive' tab if you're using the tab.

That is quite the wrong place to do research.
You may need to go to somewhere else reputable, like the websites "The Bitcoin Wiki" and "Learn Me a Bitcoin".
Links:

• Bitcoin Wiki: https://en.bitcoin.it/wiki/Main_Page
• learnmeabitcoin: https://learnmeabitcoin.com/technical/

For example: Bitcoin Wiki has an entry about 'fee rate' under "Miner Fees" article - https://en.bitcoin.it/wiki/Miner_fees#Feerates

This is quite a relatively manageable error since you wont be needing to redownload the whole blockchain unless your node is pruned.
The 'fix' is to launch Bitcoin Core with -reindex-chainstate, then wait for it to finish (may take hours).

To start Bitcoin Core with that parameter:

• Go to the directory where Bitcoin Core is installed, usually C:/Program Files/Bitcoin
• 'Shift+RightClick' on an empty space in that folder (make sure nothing is highlighted), and select "Open PowerShell Window Here" or "Open CMD....".
• 'PowerShell' will open, type: ./bitcoin-qt -reindex-chainstate (remove "./" if you use CMD)
• Bitcoin Core will open and start the reindex process.

Note: To prevent that from happening, make sure to properly close Bitcoin Core everytime you need to close it.
Do not force-close it or shutdown the PC while it's running.

You can set it in bitcoin-qt's setting or in the config file.
Since you're using QT: Open the menu "Settings->Options...", then put a reasonable value in "Size of database cache".
More or less half of your RAM, depending on the usage.

That requires you to restart Bitcoin core as the red message below the setting will say.

The log should be in your Bitcoin data directory.
If you didn't set a custom one, it should be in: https://en.bitcoin.it/wiki/Data_directory#Default_Location (check your OS)
If you set a custom data directory, just open that folder and the debug.log file should be there.

Normally, you'd copy the wallet file from %appdata%/electrum/wallets and paste it to the same directory of the new Electrum.
The you can open it with the menu "File->Open". That's to preserve the wallet data that the seed phrase can't restore.

However, you said that you've been phished in that wallet so, it's safe not to import anything from that wallet.
Let's just hope that the hacker didn't stored your seed/keys and haven't stolen the newly sent coins.

You should start cmd in the directory where bitcoin-qt is located or change the working directory using "cd" command.
eg.:
Then enter the command vv181 instructed you to use.