My wife and I honeymooned there this past September. We had a great time and thoroughly enjoyed ourselves. The main thing I would recommend is going to The Baths. I'm sure you've already heard about it a bunch, but the snorkeling there is incredible. Just ask the hotel when to go there so that you can avoid the cruise ships. When my wife and I went, there were only two other couples at The Baths. I also recommend picking out a beach each day and just going there and relaxing for several hours.
We went to Mountain Trunk, Valley Trunk, The Baths and then hung out in some reefs just off Necker Island. All of these are a must. Also, if you get tired of the beach, there are some pretty decent hiking trails at the resort. I think that one is called "Cow Herd Trail" or something like that--it's on the way up to the spa on the left side, you'll see it. It's about an hour hike, but it takes you to the top of the island and you can't beat the view from up there. You can see the whole island from there.
Day trips are cool if you're wanting to do something different. I would take recommendations from the staff on where to go.
My wife and I did the romance package as well, so be sure to do all of the things that you paid for. The cocktail cruise is fun and I recommend doing it earlier in the trip because you will be able to meet other couples at the resort--we ended up having dinner with several of them. The sail trip was awesome--we were the only couple on the boat. My wife doesn't like to snorkel too much so she stayed on the boat and read while the captain took me to some really cool spots in the reefs. One location had about a 6' nurse shark sleeping under the reefs.
Since you've already paid for the meals, eat your a$$ off. If you want 3 entrees, get 3 entrees--if you want 3 desserts, get 3 desserts. You don't have a limit on what you can order food-wise. Alcohol is a whole other story, though. The best advice we got was from the gentleman that brought our bags to the room regarding alcohol. The hotel gives you a complimentary bottle of local rum in your room, a couple of Cokes and some lime-type soda to make Rum Tings (don't worry, it's all free). When you don't have any more Cokes, order a pitcher of their passion fruit juice from room service--it's about $10. You'll have plenty of alcohol and punch for the next couple of days and you won't have to pay for their drinks on the beach. Trust me, two drinks on the beach will run you about $30.
Get the massages early in the time that you're there--it gets things started off perfectly. Lastly, keep in mind that tip is already included in your bill and you paid for it with the package. Don't get scared thinking that you'll get a bill for the tip at the end of your trip--unless of course you decide to add more tip onto the bill.
Let me know if you have any questions. I promise, you guys are going to have a blast there.