if your plane lands at 8:50 and we assume its not late, giving an hour or so to get off the plane collect your luggage and get to the taxi line, (which would be speedy time considering Miami) that puts you in a cab about 10AM. Another 15 to 20 mins to get to the port and you are at 10:30 ish. You can probably get someone to take your bags by 11AM. You can probably start boarding by 12 or 12:30. I'm not sure you would be saving yourself a whole lot of waiting time if you try to throw a breakfast in there. In fact I would say that if you do, you are ALL going to be waiting in line because most people start arriving by noon.
You might just want to skip the breakfast and meet on the ship. have a buffet lunch then.
There isn't a whole lot open at the Bayside Market that early in the morning. After our Freedom cruise ended 5/4 we took the South Beach post cruise excursion since our return flight didn't leave till 5pm. We got off Freedom at 8am, and the bus pulled away for the excursion around 9am. At 10am they dropped us off at Bayside for a boat tour and the boat left at 11am. Between 10 and 11, about all you could buy was a smoothie.
Completed first cruise 5/6/06 Voyager of the Seas - Eastern Caribbean
2nd cruise Majesty OTS - 5/11/07
3rd cruise Freedom of the Seas 4/27/08 Western Caribbean - Hump Balcony!!!
Next Navigator of the Seas 4/6/09 First time to Belize