I love that area, I grew up near there. You can catch some large fish out there. My brother caught a 40-lb flathead catfish out at Lake Marion a few years ago. I've always spent most of my time at the north end of Lake Marion, which is a bit far from where you'll be.
If you're looking for a golf course, there are tons of them. I don't know of any especially nice ones, but golfing is cheap there, especially in the heat of summer. Search under the "Sumter area" for golf courses.
South Carolina Golf - Course Finder
The lake is pretty large, and you may not want to just canoe or kayak through the middle of it. I'm sure you could, it just doesn't sound like much fun. You'd probably want to go off into the swamp somewhere, or find a smaller cove.