Bitcoin Core (and other wallet software) allow you to have full control of your Bitcoin by giving you full control of your private keys. You don't need to use it, but it allows for the some of the best security and privacy. Bitcoin Core is also a full node software. This means that it fully validates every single block and transaction. Bitcoin Core nodes make up the backbone of the Bitcoin network; without nodes, transactions and blocks would not be able to propagate well and the network would not be decentralized.

No, that statement is true. Each ADDRESS has on average 2⁹⁶. Each public key has exactly one private key and vice versa. Public keys and addresses are not the same thing.

Legacy means that you will be using addresses of the form 1... Segwit means that you will be using addresses of the form 3... or bc1... (one is for P2SH nested segwit and the other is for native segwit). Note that 3... addresses are for P2SH addresses in general and are not just for segwit. bc1... addresses are for segwit specifically but not all wallets support it yet.

Yes.

Yes. When you want to send money, transaction fees for spending a segwit output will likely be lower from spending a legacy output.

Hashpower and addresses are unrelated. In fact, addresses don't even exist on the network; they are just a human abstraction that tells the wallet what to put in the output script of an output.

No, no there are not two chains. Segwit is activated on the Bitcoin blockchain.

If you want to use segwit, get some segwit addresses and begin giving them out to people when you want to be paid. You can also make a transaction sending your coins to segwit addresses in your wallet. If you don't want to use segwit, then do nothing. Either way is safe.

No, that's not true. With an HD wallet, you still have a private key and public key for every single address. All an HD wallet is is that you have a seed from which all over private keys in your wallet are derived. Addresses and public keys still work in the same way as randomly generated private keys.

The lightning network is not something that was proposed by or being worked on by Bitcoin Core developers.

Because we don't know how Segwit and the deployment of LN is going to effect the economy and the transactional capacity. There are consequences to increasing the block size (and there are positives to having full blocks and a mempool that is not emptied on every block) which we do not think are worth having for a larger block size limit. The lightning network is not yet deployed and increasing the block size limit further may be more harmful than not.

Not really. The people who are connected to those hubs can close channels any time that they want. So if a hub is being a dick and refusing to close a channel, then you can close it yourself, albeit you will need to wait a little bit before you can access your coins. Likewise you can do the same the the hub. Furthermore, if a hub were to be engaging in that behavior, many people would likely just stop using them. They would close their channels with that hub and route payments through someone else. Anyone can be a hub, so there likely won't be a shortage of alternative hubs to use and that people are simultaneously connected to.

What makes you think that? There are at least 2 other organizations besides Blockstream who are building software for LN. They employ more people than Blockstream does and all of them are collaborating on making their software compatible via the Lightning RFC spec.

You overestimate the manpower and influence of Blockstream.

First of all, as I said earlier, anyone can be a LN hub. You don't and shouldn't be connected to only one hub. There will certainly be other hubs set up by the other LN developers for people to use.

Secondly, Blockstream is not behind Bitcoin Core nor do they control Bitcoin Core in any way, shape, or form.

Delete the files peers.dat and banlist.dat which can be found in the Bitcoin Core datadir. Then start Bitcoin Core.

Every version of Bitcoin Core brings new functionality. The accounts system is not a consensus rule, it is an internal Bitcoin Core thing so it will be removed when it is implemented. This is very different from Segwit which is a consensus rule and required activation from the rest of the network.

Yes, Armory uses Bitcoin Core and Bitcoin Core must be synced for Armory to work. Bitcoin Core must also be running when Armory is running (Armory is configured by default to run Bitcoin Core automatically).

Can you please post your code for setting up the block store?

It looks like the problem is that tally is null which implies that the implementation of fullprunedblockstore is incorrect.

I am certain that the problem you are experiencing has nothing to do with bitcoind or any settings. Rather I'm fairly certain that this problem is because it is throwing an exception when trying to validate a block which is causing the networking portion to crash and thus disconnect.

A timing mishap in this context (with the pong message) is a pong message which has an old nonce value that is not expected. Can you please post your debug.log file with those values unredacted? Without being able to see what is actually being reported, it is hard to say what is wrong.

Transaction verification flags are the rules that are used in validating transactions. These rules include the standardness rules and other node policy rules that are not consensus rules. You cannot see what they are in bitcoin-cli; you will have to look at the source code.

Run Bitcoin Core with the -debug option. You are already running with debug=net which is enough to determine whether a block is served before disconnecting. Blocks are definitely being sent before the socket is closed and disconnected.

Yes.

The block and transaction verification flags have nothing to do with the networking. All consensus rules are the same, but some node policy rules are relaxed to allow for non-standard transactions. locktimes are a consensus rule.

The protocol has changed since the full node stuff was written and it has not really been updated since. It is also experimental.

Is Bitcoin Core installed? If not, install it.

If it is installed, is it running? Is it fully synced?

This is not a script. It is a server software.

Read https://github.com/achow101/BitcointalkAccountPricer/blob/master/INSTALL.md

Use Armory 0.96.3

You have the backup phrase. Restore your wallet from that backup phrase. That's what the backup phrase is for.

Just because you don't know what you are doing does not mean that all is lost. Just because you don't know what you are doing does not mean that no one else knows what they are doing.

You will get addresses when you get a wallet. The wallet software will handle all of that for you.

It sounds like you sent USDT to a Bitcoin address. USDT is not Bitcoin and is incompatible with Bitcoin (although apparently it uses the same address format). It is possible to recover your coins, but that is very difficult and requires handling private keys and installing a USDT wallet. However it seems like you sent USDT to Coinbase, and it is likely that they are not able to do this. Besides the fact that it requires a lot of work, their private keys may not necessarily be accessible to be imported into a USDT wallet. Your coins are probably lost, and there certainly is no transaction that is stuck.

You paired in the wrong direction. If you scanned a QR code or entered the backup phrase from your computer onto your phone, then that is wrong. You should have entered a backup phrase from your phone onto your computer.

No, that is not how unspent outputs works. The final balance would only not be the same as amount received if you have spent any Bitcoin.

Some other mining pools may also offer acceleration services. I don't remember. However any mining pool operator can accelerate transactions for you.

You don't have to, but I recommend that you do.

It depends on your hardware and network connection. It can take anywhere from a few hours to a few days.

Use your own account system. Use an external database to handle your accounts and what each person's balance is. Don't try to make each address belong to certain accounts (the Bitcoin Core accounts system doesn't really work like that anyways). Or you can use the multi-wallet feature and have each wallet be an "account". However Bitcoin Core may not be able to handle hundreds or thousands of wallets with multi-wallet. It really is not designed for that use case.