Hi creativedisco, welcome to CruiseReviews! Congratulations on your up-coming cruise. There's not much more I can add, but a warm welcome:) I agree totally with negative reviews, it is all subjective. I've read some horrible ones about ships I have had a marvelous time on, eaten food that I thought was fantastic on ships that people have said it was swill, and gone on excursions that have been incredible that others have said weren't worth the money.
I do try to be very honest with my reviews, and can honestly say I have not had a bad cruise, just some better than others. I'm by no means an expert, but have enjoyed cruising for many years and would not trade a cruise for any other vacation.
I'll almost guarantee, you'll come back from this one and be hooked like the rest of us on this board. I try to warn all new cruisers that cruising is very addictive!
7 mile is a beautiful beach, and so is Rum Point. The big attraction in Grand Cayman is Stingray City, but there is some great snorkeling there. Cozumel has so many great beaches, it's hard to say which my favorite is. We're going to The Money Bar in December, just for a change. We've been to Chankanaab Park, which is probably my favorite because there is good snorkeling plus all the ammenities, Paradise Beach, and have rented a scooter and stopped at each one for a look around. Nachi Cocom is a very nice one, but you have to reserve ahead of time, they have a limit on how many they allow in.
Take a look through the Caribbean Port Chat section of the board, too. You might find some great ideas there.
Have a wonderful cruise!