Just thought I would offer my advise as well, although Dave gives pretty good advice. As he stated, the all aboard call for embarkation is 90 minutes prior to sailing. Even though FLL is only about 10 minutes from Port Everglades, I would plan on a flight arriving in the morning before noon if you must fly down the day of. I've done this on my past cruises, and never had a problem. My home airport is a hub, so I'm lucky that there are multiple flights, including early morning flights, down to Florida.
As far as your return flight, I've always booked an early afternoon flight for the reasons Dave stated. Also, from what I've read in another post, if there are multiple ships loading / unloading, the roads in Port Everglades can get backed up onto the highways. If you did book that 11:00 am flight, I would do self debarkation. Like Dave stated, you must be able to physically carry off your own luggage with no help from the staff.
2007 - Majesty of the Seas
2009 - Enchantment of the Seas
2010 - Freedom of the Seas