I have some questions about purchasing Amazon gift cards

So a good friend of mine lives in the UK, I live in continental Europe. I want to buy her an amazon UK gift card for her birthday, but I had some questions.

Firstly, how does it work? Do you just enter an e-mail address and then it sends the code to it?

Secondly, if so, can I just have the gift card sent to my own e-mail address and then give her the code myself? Would that work?

Thirdly, I've read somewhere that you have to have have your credit card linked to your amazon account to cash in gift cards. Is this true? Because she does't have a credit card.

Finally, I've heard a LOT of stories about amazon accounts being banned because they tried cashing in gift cards. Would my friend be in danger of that if I gave her a gift card code?

Thank you all so much!