I think this is a cute idea. And Ends, me and my group do the same thing with our audio. We have to have it pre-recorded, and one of our girls has to put together our track. Its a lot of work. @@ We just practice like mad women to get all of our parts down right. Since you'll have music on your track, its easy to know when you have to go based on which beat of the song comes up next.
This actually makes me think of this skit that I saw at Fanime. It was wonderfully put together, and even won a group performance award. :3
Just skip 30 seconds into the video to where it starts: http://www.youtube.com/watch?v=5ptx9zNASDk