That might be the problem. You are using an old unsupported os.

Yes. You can import the wallet.dat file into blockchain.info's web wallet and perhaps other wallets too. However, if you do that, I would recommend that once the wallet is imported, to move all of the Bitcoin to a new wallet and not receive any Bitcoin on addresses from the old wallet.

The miner can put whatever he wants into it. He could put the coinbase sig and impersonate some other miner if he wanted. Once the block is mined, it becomes immutable, but the miner has free reign over what goes inside.

If you could connect to every single node in the world, then it would be possible to identify which ip address first relayed a block. That node would be the person who found the block and that ip address could then be associated to a name.

Theoretically your transaction could be lost. Some nodes will rebroadcast transactions, but the only one that reliably does so is the node that created and sent the transaction initially. It will rebroadcast every 30 minutes AFAIK. However, the transaction will stay in the mempools of other nodes for a while before it is either confirmed or dropped.

They don't always have the correct info either. You can see this thread https://bitcointalk.org/index.php?topic=123726.0 to read more about it.

Yes, but the merchant should never ship their products without having at least 1 confirmation.

The other nodes will not relay it and upon restart, they won't have the transaction.

Full RBF means that you can replace the output addresses, but what is currently recommended for use is partial RBF. This requires that the inputs and outputs remain the same as the transaction it replaces but the only difference is the fee.

I don't have a link, I will get back to you with that if I can find it. However, I know this after looking in the source code. Nodes will only relay transactions once when they receive it or when another node asks for it. The sending node will continue to broadcast the transaction while it is unconfirmed. If it stops broadcasting it, over time nodes will begin to not have the transaction in their mempools, either from restarts or other rules that people might set. Once enough nodes have dropped a transaction, a double spend can be attempted and if that double spend is confirmed, then the original will be dropped as a double spend.

The coinbase tx is the first txid in the array tx that you see when you do getblock. In order to get the transactions data, you need to do getrawtransaction to get the transaction data. In order to get transaction data from Bitcoin Core though, it needs to be started with the -txindex flag in order to see transactions that aren't yours. This will require a rebuild of the entire blockchain so that it can have all of the transactions.
To get the data from get raw transaction:
The 1 makes it verbose so that you get the transaction decoded instead of just hex data. There will be a field labeled "coinbase" in the coinbase transaction and that contains the pool data you are looking for.

They don't require it, but many people on localbitcoins will be less likely to conduct trades with you if you don't verify your identity. They will be more cautious and you may not able to buy as much as a verified user.

It depends on your country. I don't know about the UK, but I know that the US has anti-money laundering laws and know-your-customer regulations that require id verification. If the exchange operates in the US, you can assume that these laws will be in play and you will have to go through the verification required by said laws.

At some point, the network will "forget" you transaction. You just need to either delete it from your wallet or not run your client for a few days. It will be as if the transaction never happened.

Here is an escrow list: https://bitcointalk.org/index.php?topic=108716.0 All of these people provide escrow services and are trusted escrows. You can choose anyone you like to be an escrow for you.

You can create a double spend with Bitcoin Core using console commands. Also, since some nodes won't relay or accept transactions with low fees, changing the fee get the double spend accepted into some mempools when the original did not. Otherwise, nodes that enabled Replace-By-Fee will allow double spends as long as the fee is greater than the original and nodes that are Bitcoin XT will relay double spends.

Just also backup your wallet.dat, but you have already done that by backing up the data directory. Everything should be safe for you to upgrade.

The hex of the coinbase transaction has a a part, I don't remember where, that is called the coinbase signature. It is simply ACII text encoded in hex. Most pools will put their own signature that indicates that they mined the block. However, it is not always reliable since anyone can put anything there, but it gives an idea of who was the miner.

By value do you mean price? The price is not set, nor is there an official API for it. You can however go to each of the major exchanges and use their API to retrieve current market data and create your own price of Bitcoin calculation.

So a block size limit increase would fix the problem because for this to be profitable, the attacker needs to have at least half of the block be legitimate transactions and that there still be a backlog of transactions, yes? And since there isn't that much real transaction volume, raising the limit to the suggested compromise of 8 Mb would solve this issue for now since it suddenly becomes unprofitable to continue to attack until transaction volume increases.

How about an advanced or expert user mode where I can select which inputs I want to use and lets me spend unconfirmed transactions. Also include RBF (replace-by-fee) and CPFP (child pays for parent) so that I can get some unconfirmed transaction confirmed.

I would spend less with Bitcoin since every time I want to make a purchase, I can see how much I actually have, just like carrying cash. I can see I have exactly this much and can only spend this much whereas credit and debit I pay before actually seeing my balance.

Interesting idea there. So what if someone manages to cause it to deflate or inflate dramatically in a very short timespan, say they bought millions of it and caused the price to rise. Would the miners only be able to recover it back to the target by changing the next reward by only 1 coin at a time?

You need to use pywallet to open the wallet.dat file and delete the keys.