Llechwedd, I hardly know where to start!
You state that ALL English pensioners who come to live in Wales make NO attempt to integrate?
You must have come across a few who have led you to that conclusion and disappointed you, but it certainly is not the case in the majority of people who live/work/retire here.
How do your views differ when it comes to those who moved from England to Wales during their working life? They contributed, still are in many cases, and then retire.
What about those who are English by birth, but are currently working in Wales? Whether they be 24 or 63 years old?
What about people from say, Poland? who are earning minimum wage in Wales, so pay no tax, but still retire here?
I would imagine that their pronunciation of Betws-y-coed might be worse even than an English person?
I could go on, and on..... but that's enough to wrestle with for starters.