I can’t speak if you are holding a non-US passport because US immigration & customs can be nuts at times. With a US passport, one hour 30 min, is more then enough time in CLT.

I've taken the LGW->CLT flight several times and with checked bags, the worst it has even taken me is 45 min to clear customs/immigration & security. Most of the time, it has taken me much less. CLT is very walk able and it does not take much time to traverse the airport.

On the US A330, in Y the first coach cabin (Rows 8-20) seems like it has a little more space then the rear coach cabin. The layout throughout Y is 2-4-2. These birds have Empower and AVOD at every seat in the plane. When you make a reservation you can get a seat assignment.