After watching this piece for like the 4th time I really like it. I saw a definitive beginning, middle (climax) and end. The beginning had a really great "free spirit" vibe. I used to skate, and when I think about skateboarding I remember it was all about feeling of the moment. I think the opening with the various soundbytes under video really captured that idea.
The middle or climax was definitely the wrecks scenes. A staple of extreme sports. That was an exciting element of the story that really gave it some punctuation.
I thought the closing soundbyte worked well, but I really could have gone for a better closing shot. How about a super wide shot of the entire park filled with people? That would have left me with a better sense of closure.
Also, did you consider actually getting on a board and getting some shots with movement in them? Try hopping on that board and getting some shots with the ground whizzing by. Someone would have loaned you a deck for that. Or if you don't feel comfortable getting on the board yourself, you could set the camera on the board and run or walk along side it and get a first person view from the board. Those are the risky shots I always love to get
As effective as fast cuts can be sometimes, I wouldn't have minded seeing more tricks from start to finish.