Re: But do we want a UK region?
US courts believe that a US search warrant can be used to make US companies (such as Amazon) produce data they have, wherever it is stored. Even if it's in the UK.
This is currently being appealed, so there's a chance the lower courts get overruled and common sense wins.
See https://en.wikipedia.org/wiki/Microsoft_Corporation_v._United_States_of_America