Jtbullet,
Greetings. Just loaded up FragMotion. If you Use CTRL+M, while in mesh mode, the supplied mesh will be deleted from the model. The rigged skeleton is left intact, and fully animated. There's an icon (the big "X") to the right of the file menu for the same thing. Make sure you "Select All", or nothing will happen.
$20 bucks? This is just the ticket for customizing FPSC models and bringing in your own. TGC should work out a little something with these folks, and integrate FragMotion into the engine.
I hope this helps. Anything else I can find out, I'll share with the room.
Thanks,
Seth Black
"...I'm sorry, could you repeat your question a little louder? I'm a trifle deaf in this ear."
- Willie Wonka