Very cool document! The sound synchronization seems to work pretty well for me in previewing; can you elaborate more on what you mean when you say it doesn't match? (also note there are some export contexts such as older browsers, iBooks, or file:/// urls where it can't be as well synced).
As for collision detection in physics, this is a popular feature request we'd like to add. Some intrepid users have figured out ways to do it with varying success until Hype has a built-in solution. Here's a few posts: