We fly to Tampa every year with BA. It's a really good service, although it has become really busy in the last couple of years - very full flights!
They seem to have improved immigration in the last couple of years - it was a lot quicker last November, but try and get a seat on the plane as close to the front as possible. Always helps!
Tampa airport is fine, really small duty free, but then that seems to be deal in all US airports. There is a TGI's, and a Le Meridien (I think it's Le Meridien, may be another big chain, I'll have think) hotel attached with a pool terrace which is great for some last minute relaxation before your flight home.
If you havn't rented a car already, definitely go for one who have a presence in the airport building - Alamo have moved offsite and it is a pain to get to - plus it is then easy to get lost when you come out of the airport. Definitely Hertz, Budget and Dollar have desks, but check which others do - we always use Dollar through Airline Network - can never find cheaper.
It's an easy drive to Orlando, but it is going to take you 2 hours even on a good run.