Pure noob here. Sorry!

I have decided to take the plunge into bitcoin investment. I am thinking of around £1000 ($1300) and leaving the investment alone for 3 to 5 years. Half in BTC and half in ETH.

I have done loads of reading (the bitcoin value has increased $700 since I started doing my research!!) and I am here to have you experts sense-check my understandings to ensure I have it all right.

Wallets:

- My understanding of wallets is that it is simply an address. That address appears in the blockchain when a transaction happens, so there is a historical record of it. This is how we know what coins are where, and how many there are. (A bit like a commit ID in Git?)

- Your wallet address is all that's needed to receive coins. But to send coins out you need your private key. If you compromise that pair (wallet address and private key), someone could take all your coins. If you lose your wallet address and/or the private key, you can never get your coins back.


Questions:

1) Is the above understanding correct?

2) If I am going for long-term investment, I should use a paper wallet. What's to stop me keeping my wallet address on one piece of paper and my private key somewhere else? So the two aren't kept together.

3) Can I choose my private key? For example, could I generate my private key from the first paragraph of my favourite book? That way I will never have to write it down nor store it with my wallet address. I will never forget it, provided I use the same method to recreate it each time I need it.

4) Does my wallet address ever change?

5) How do I create a wallet? Is the address allocated to me?

5) Living in the UK, where can I get my coins from in the first instance? I've heard bad things about Coinbase. What is this localbitcoins.com website? Is it safe to buy this way?

Thanks for your help.