I'll do my best to reply to everything in order...
Here's a video:
http://www.youtube.com/watch?v=e7zD_Qd1mG0 we've made some modifications since taking this video, and have dealt with some of the Frisbee jumping and slipping on the fence.
We've replaced one of the big CIMs with a smaller one, and will probably take off the third wheel...
As far as the wheels slipping on the shaft itself, we're using shaft collars with locking screws and the wheels aren't going anywhere.
as far as local teams, MVRT has been helping us, but they aren't close enough to be of much help at this point (they're the closest at about a 1.5 hour drive away)
Thanks!