Can an AppleTV be bought anywhere and used anywhere else or is there any regionality? I want to buy an AppleTV in the US and use it in the UK - will there be any problems playing content bought on the US store in the UK or vice-versa?
You can use it wherever and buy what you want. No regions. No problems. I am speaking from experience. I have used/ bought and played Apple content and Apple TVs in Italy Australia US and UK.