Your node is pruned just like HCP guessed:
Bitcoin core automatically set it on when it detected that the data directory cannot contain all the blocks and other files.
So first look for bitcoin-qt's prune settings in "Settings->Options...->Prune block storage to", if it was ticked, uncheck it.
Also, if you've created a bitcoin.conf file in bitcoin datadir, remove any entry for pruning and if you're running using a shortcut, check if you've added any pruning parameters.

Finally, after disabling it, you'll need to sync Bitcoin Core again from start.
But make sure that you have at least 4000GB of free space in that disk.

Those are already pre-generated in the wallet file, 1000 receiving and 1000 change addresses. They are not randomly generated, all are based from your "hdseed".
In the 'receive' tab, the first to be displayed is the first in the index, the next is the second, etc. etc.

If you really want to "see" them, you can use dumpwallet command (doc), but that includes sensitive data like the hdseed, extended private masterkey and the addresses' private keys.
So, only do this to a "for testing" wallet.

In the data dump (include a .txt extension if you want to open it directly with a txt editor),
look for the derivation paths like hdkeypath=m/0'/0'/0'.
The example should be the first address that displayed in the receive tab, hdkeypath=m/0'/0'/1' is the second and hdkeypath=m/0'/0'/2 3'is the third.
The change addresses' hdkeypath starts with hdkeypath=m/0'/1'/0' then hdkeypath=m/0'/1'/1' for the second, etc.

Lastly, the wallet will generate more keys to keep a 1000 unused keys per chain after you've used the first in the index.

The app doesn't support signing a message natively but you can import the "recovery phrase" you can get from the 'setting icon' to a wallet that supports BIP39 seed.
I'd suggest Electrum and sign a message using it, your Bitcoin address should appear first in the 'addresses' tab.

Here's a short tutorial:

• Get your Coinbase Wallet App's "recovery phrase" in the Settings (you need to type your pin), that's the 12-random-words, copy it to a piece of paper.
• Download Electrum [link] (Stand-Alone if Windows) and I'd recommend you to verify its signature [tutorial], then launch it.
• During wallet creation, select the options: "Standard wallet->I already have a seed->type the recovery phrase->Click 'Options'->tick 'BIP 39 seed'->Next."
• In the next window, select "legacy (p2pkh)" for address that starts with '1' or "native segwit (p2wpkh)" for address that starts with 'bc1', depending on what you need to sign.
• Finish creating the wallet, I'd recommend setting a strong password; once done, enable the addresses tab using "View->Show addresses", then click "Addresses".
• To sign a message: Use "Tools->Sign/verify message", type your message, paste your address and click "sign", the signature will appear, then format it using the guide in the OP.

BTW, messages signed with the SegWit address wont be valid for most clients, only Electrum and others (I don't know any other client),
you must include that as a note to whomever you're sending the message to.

Important note: Make sure not to paste the seed phrase to any text editor, online posts or email, that alone can control all of your funds (you can do the message signing offline).

That speed looks like Bitcoin core is syncing in the background instead of Armory 'preparing database'.

Is the path to Bitcoin's directory correctly set in Armory? The one you've set in HCP's reply "-choosedatadir".
Because if it's not set, Armory will launch bitcoind with the default bitcoin datadir and since the blockchain isn't there, it'll sync from scratch instead of using the already downloaded blockchain.
You can set it in "File->Settings->Bitcoin Home Directory" and restart Armory (close any lingering processes before launching Armory, or restart PC).

Which of the transaction to bc1qz6k55y7z20azt596u80mtp0p53v9qnrj534t3k is yours?
But since you've mentioned "mining address" and "cant be changed", I'd take yours is the one from this address: 1Jucx1ny7mpxWwTfqVt4LTNyT4NPeosDs6

My question: is that a vanity address? If yes, where/how did you create it?
Because there are a couple of online sites where you can create compromised vanity addresses.

That's the same link OP mentioned in the first post and it didn't worked, he said it returned with "invalid checksum".

Thanks but that's already covered by the previous posts (that I've merited) plus I'm talking about reducing the time-frame for a "replay attacker" to do his job.

Quite off-topic answer: As long as you're sending to your own wallet and it's non-custodial, you don't have to worry that much about 'replay attack'.
But that attack can still damage you if the "replayed" transaction's output isn't standardized by the other chain, making it hard to spend, non-spendable or anyone-can-spend depending on the script;
so try to use the address type that's supported by most of those forks.

Or course the faster you can send the 'forked coins' to a new address after the first transaction (from any chain), the lower the risk.
Send/Sweep them to their respective wallets as fast as you can.

He's currently offline, but I believe the command with that result is getmempoolinfo.

Let's try common terms:
The negative balance that you're seeing is just displayed beside your current balance because it's "pending".
Once it got "processed", it will be deducted from your current balance.

But it comes with a fee so, it may be higher than what you've input in the send tab, it depends on the 'fee rate' that you've selected in the slider and the size of the transaction (not amount).
To check the details, go to the history and double-click (under the date column) the unconfirmed transaction with "red" amount.

Try variations while following post number 2.
Because the "custom word(s)" can be the 13th, 14th, 15th to 16th words.

So in Electrum, you should only paste 12 in the "enter seed", tick both boxes in the "Options", and if it says "BIP39 (checksum: ok)", proceed and click "next".
If false it's not a 'BIP39 seed', uncheck BIP39 and see if "next" is clickable, if not, it's not an 'Electrum seed',
If 12 didn't work, try variations like different number of words (first 3,6,9,15) with 'BIP39' ticked.

In the next window, paste the 'rest' of the words, 'two' or 'last' of them; then finish creating the wallet and see if your address shows up in the address tab ("View->Show Addresses" to display), if you don't know an address from your wallet, wait for a few minutes to sync.

Based from an example in the pull request's comments (bitcoin/pull/15935), it should take some settings from the bitcoin.conf file but in json format.
I don't know if all or which settings will work though.

I've tried some,
example1 (disables wallet function):example2 (produces legacy addresses in the receive tab):

The problem is: despite the very high fee rate of those two transactions, their parent transactions are both unconfirmed with very low fee rate.
So miners are considering them as "bundle" parent and child transactions, and the fee rate will be based from their total size and fee.

Your transaction: 6cdb98f9c86ef7902ee991d44e013307662086322dc41ee392584daac8b12d11 with 100.1 sat/vB fee rate has two inputs which are both unconfirmed, namely:
1. 0ba52bed104cea1075754f783867d423ae9510bd4d6fb3f3905aaf7e1862fd9d @ 7.0 sat/vB.
2. fe682ab28ecdb3bc82498af0c7730e2fcb0cf8563c6fc88cc2367c16aa3624a0 @ 10.0 sat/vB.

Both the transaction's sizes are too large and the fee rate too low for the child transaction to accelerate them effectively.
let's say that there are no unconfirmed transaction in the parents' inputs (I didn't checked because there are hundreds of them),
the total size of the batch would be: 699 vB + 27904 vB + 16106 vB = 44,709 vB
then the total fee would be: 70,000 sat + 195,860 sat + 161,530 = 427,390 sat fee; that's a total of 9.56sat/vB fee rate[/b].
Currently, 9-10sat/B is @ 20vMB from tip of mempools.

The other transaction may be missing from time to time because the parent's input parent's fee rate range is beyond the default maximum size of mempools.

Philipma did a benchmark using a similar specs in a thread somewhere in Bitcoin Technical Support board and he thought that the bottleneck is his (200mbps) internet since he's using an SSD and latest hardware.

Here's the link: Re: Faster sync would be nice (i.e. soooo slow)
Summary: with the latest specs and fast internet speed, he's able to sync Bitcoin Core in just 6hours, garyf22's internet may be slower but his specs should be similar.
What he didn't accounted is the download speed will also be based from his peers.

Increase your "database cache" to a reasonable amount like half of your RAM as long as the capacity isn't used by other programs, default is too low.
The option is just below 'pruning', then restart Bitcoin core.

It will be slower when you reach 70-90%.

From the looks of it, OP is confused of lightning and he thought that mainnet and lightning funds can be sent though either network.

Let's say that you already have an open channel and you go to the send tab:
If you paste a Bitcoin address there, Electrum will send a normal transaction and spend your on-chain funds.
If you paste a lightning payment invoice there, Electrum will initialize a lightning payment.

It depends on what you've pasted; bitcoin addresses, on-chain payment invoice (eg. from payment processors) and lightning invoice (long string that should start with 'ln') are very very different from each other, you do not have to worry about losing funds.

And read Abdussamad's reply.

P.S.: it's "SegWit" not "WetSig" (sounds kinky)  

Are you sure about the year?
Bitcoin was just released that year and it's hard to imagine that a service that gives some sort of "verification code" existed.

You might need to search for a private key that your dad might have exported from Bitcoin core through a third-party program.
That should look like a string of HEX Characters (0-9, A-F) consisting of 64characters; if newer that you expected, 51 BASE58 characters that starts with '5'; or much recent, starts with 'L' or 'K'.
Also look for a file named "wallet.dat".

One the side note: with all those "lol", it's hard to take this seriously.

The "verification code" part is not promising, because if it's from 2009, then he must have used the official client which doesn't have a verification code.

Σ( ￣□￣||)

Note: Bitcoin Core won't download the "remainder", it will sync from start all over again.
Also, you need to close it and run again after unchecking the box to disable pruning.

That's it, so Electrum will automatically disable the feature when RBF is available, that's a well-thought feature.
Must be because it's not efficient to allow the sender to create another transaction to accelerate the one that can be RBF~ed.
I haven't tested that factor, thanks.

Anyways, the CPFP will only able to send to his own wallet, being able to use 'coin control' will allow him to use the coin for his next payments/transactions instead of sending back to himself.

In terms of dollars equivalent, yes for now.