"kelton, dining room manager..." Sounds like they replaced previoux managers. Good. Blackbird is a very cool place, but... When we were there end of July, management was awful. Spent more time playing volleyball than doing his job.
My friend was completing her open water dives for PADI certification and using their equipment. She was given a bad tank and two bad regulators, the second of which crapped out while she was in the water on her first open water dive ever. So, make sure you take your own equipment.
They use DM's they pick up in Belize City who are not FT employees, so you don't know if you will get a good one or bad one. We mostly dove with the instructor so that was allright, but I did dive with the DM a couple of times, and he was awful (no safety stop at end of dive. raced ahead without bothering to look back to see if we were following) so you might want to get the rules straight before you get in the water.
Oh, the trip to the Caye is long (1 1/2 hours) and can be rough and wet. So, you might want to take a waterproof shell and something for seasickness if rough seas bother you. OTOH, make sure to do the Blue Hole trip. The Blue Hole is okay, but second dive after our interval at the Aquarium was the best dive of the week. Have fun and report back on how you liked the trip. I'd go back if the management problems are resolves.