In planning off resort activities, you need to first realize that you will only really be at the resort for 3 days and one of those will already be taken up with wedding festivities. Your first and last day will be spent traveling. For 3 days, I wouldn't plan much off resort. As Blondie said, sand gravity has a way of kicking in and taking over. If you do want to take a trip, I suggest the tour of YS Falls, the Black River, and Pelican Bar. This is a full day trip and will show you the island as well as take you on some cool nature stuff. The resort can set-up this tour for you.
There are also lots of activities at the resort that will keep you plenty busy. Especially for only a couple of days.
As far as renting a vehicle/scooter, I highly recommend against it. The rules of the road are very different in Jamaica plus they drive on the other side of the road. It is MUCH wiser to hire a taxi which the resort can handle for you. Be sure you negotiate the price before you get into the cab and only use cabs with red license plates. Those are the ones who are licensed and insured as taxi drivers.
The resort has 2 snorkeling trips per day and it is some fairly decent snorkeling.
All of the restaurants serve seafood. There are also a couple good restaurants on the Cliffs in Negril. The Rockhouse is a good one to watch the sunset over the ocean. Catcha Falling Star also gets really good reviews.
Juliann & Jeff
Jamaica Soon Come