You will be on Celebrities new ship, we are joining it in April in the Caribbean. We have had no problems with Celeb they do our flights and transfers save the hassle coats a bit more, but they would fly you out the day before your travel agant should have pursued this at the time of booking you could always go back and ask them now. Likely you will fly BA to and from Rome our flight back was 1 p.m. but off the ship around 9 a.m., maybe slightly earlier. We don't know yet how well Celeb will have adapted to 2,800 passengers departing with all of their others are around 1800/1950 passengers but look out for the reviews from January/February 2009 onwards. On an early arrival I can't remeber what time we got to the ship but we had Edin/Heath Heath/Rome to do but I think we arrived around 2 p.m. and the ship sailed at 6 with muster drill around 5.30 p.m.
Very difficult to tell this early but you probably said you wanted to fly out of Gatwick because of where you live. I would suggest that give them a ring on 01932 834 326 and ask for the Air Co-ordinator. There is a chance that if you have an early flight out you may be routed via Munchen and the same on the way back and that is one awfully long experience. Far better flights out of Heathrow as a rule. ... Neil.
Flight itineraries for Aug09 will not be out till Oct08. Celebrity will route you with whoever they have contracts with - but out of LHR there is a chance of a direct flight. If you want to go out a day earlier, then call your T/a and they will call X and get them to amend the booking. If you go out earlier and if you do not sleep at the Celebrity hotel then you lose the transfers, but it is easy to get to Civitavecchia by train.