Just want to point out that using a static rope for top-roping purposes is considered ok amongst outdoor professional climbing circles. Falls in those circumstances tend to actually be sags instead of whippers, and static lines tend to be more durable than dynamic. Since it has a limited application - you can only use a static line where you don't need to lead the route to establish the top-rope - you only see it at select crags with a select crowd.
The problem is simply that the OP insists on using a rope that's TOO BIG. Replacing the rope with a rope SMALLER would result in a belay/rope combo that is JUST RIGHT.
I'm starting to feel like freakin' Goldilocks here.
