We just got married at Ceiba Del Mar on 10/24/10 and it was absolutely wonderful there! We had 24 rooms booked and let me reassure you Paola Sanchez (the onsite wedding coordinator) did a fabulous job, from a beach bonfire one night, a rehearsal dinner the next, to the day of the wedding, and through the reception, everything was seamless. Now to answer your questions.
1) We did a symbolic ceremony, but used a local officiant, Pam Lopez. The legal ceremony seemed like too much of a hassle. Plus we wrote our entire ceremony so it was more personal to us.
2) We were supposed to have the reception on the terrace, but due to the weather forecast that evening (thunderstorms!), we had to move the reception indoors just a few hours before the wedding. I had requested 20 (2x10) hanging lanterns for the terrace which they wound up using on the floor of the indoor room and they lit up the room nicely. plus some candles on the tables. I think the lanterns were around $300, but would have to double check that. I used Gabi of Planner1 events and everything looked exactly as I had requested, just unbelievable because I think I'm a pretty picky person, she was so easy to work with and very professional. I'll try to post pics shortly, but feel free to e-mail me directly and I'll send you photos of my flowers and decor.
3) For the ceremony music we just burned a cd and used the resorts sound system out on the pier which worked great. For the cocktail hour we had a Mariachi Band that Paola had arranged and they were excellent! For the reception we used DJ Mannia, and they did a fantastic job. Almost our entire party was up and dancing the whole evening. They really know how to cater to the crowd.
4) I have no idea on what the steel drums would cost, but that sounds like a really cool idea! I bet Paola or Gabi would be able to get a price for you.
5) We did the 3 course dinner and it was very nice. But instead of having everyone pick an appetizer, entree, and dessert, we just had them pick entrees. We went with the proscuitto and melon appetizer, then the guests had a choice of Angus Beef (which was a filet), Sea Bass, Chicken, or Vegetarian. Then we did creme brulee for dessert. Plus we had the chef make us cupcakes instead of a traditional wedding cake.
I hope this helps with your decision making. Please feel free to contact me if you think of anything else, good luck and happy planning!