Funny you should ask;
if you haven't come across it already, read the response I posted at 6:04 p.m. to raffles thread,"Princess vs. Carnival out of NYC". The only place on your itinerary I've been is Cozumel, and all I did there was snorkel and frankly, it wasn't the best. But anything else I can help you with, I would love to try.
Bye for now.