Which cabin you have on the Oasis doesn't matter much. They are all comfortable.
Booking a flight which arrives at FLL at 2pm was a bad idea. Although the ship has a published sailing time of 5pm, federal security rules require all passengers to be checked in and aboard no later than 90 minutes prior to the published sailing time. This means that you must be aboard by 3:30pm even if you do the on-line check in at the Royal Caribbean website (which you really need to do at least 3 days prior to the cruise). They can and will refuse to let you board, and you won't get your money back. The only likely exception would be if you booked your air through Royal Caribbean. If you booked your own air I'm going to tell you straight up - you need to rebook for a flight that arrives no later than 12:30pm. And since you need to do that, you really should consider flying down a day early and spending the night in a hotel.
The departure flight should be okay.