1. Yes, you can register an American Amazon account (the address should be filled in the United States). When you go to Meiya to buy books, kindle should switch to Meiya account, and you should use an agent (American ip) when you buy books, otherwise it will be easy to be blocked, and you can pay by credit card or Amazon gift card. There is nothing to say.

2. Needless to say

3. The machines are exactly the same, and there is no difference in functions. If you have Amazon accounts in various countries, you can buy books everywhere, as long as you pay attention to the ip address (locally or by using an agent). The only difference is the warranty, where you bought it.