Very impressive! Couple questions.

I assume the model has to be bone-based?

How do you set the force of the 'hitting' object? For instance in a real game situation, let's say your character has two weapons he can switch between: a gun and a shotgun. The impact onto the ragdoll enemy would be very different with these two weapons. How does your system account for that?

Will it only work with bipeds? What about a four-legged enemy?