Candy, Don't know of you have tried this yet but if you use the "Island" link at the top of this page, then the "Maps" link you can get a very detailed map with businesses on the island.I don't know how well to scale it is but we stayed at Coconuts and Playador
and i will guess it is 1/4-1/2 mile walk to downtown. Maybe that can help you judge the walking issue.
But, not to worry, golf carts are cheap!