England really isn't that big, so any of those things are only a few hours away by car at the very most.
I wouldn't have thought anyone would bat an eyelid at an Irish person, so I wouldn't worry about that. We're massively multicultural, it's just the small pockets of racist idiots and the Daily Mail that make it seem like sometimes we're not.
Being in the North West, we've got the Lake district, the Peak district and Wales all within easy reach. The countryside is lovely, the cities are great and there's something for everyone's price range.
I don't know if it's the best place? I imagine what you have to spend will dictate where you live, London's going to be hugely different to the North East for example.