i called yesterday, 5/12/11, and from what i was told, the use of everythin is available..tramps and foam pits included. skateparks...
and regarding payment, everyone registered will get a email soon with more info. they told me that you can either pay your 340$ at check in when you get there on the Day 1, or you can mail them a check for the money due. also, as long as when you registered and got a confirmation email, you are registered. if you didnt get an email or dont remember getting one or just wanna make sure, just give them a call, they are super nice.