Creating a ragdoll fitted to a given armature

Hi guys,

I have a specific armature, i want it to be copy location/rotation when the physic is activated. So when you creating the ragdoll boxes, do you center the boxes on the origin (= pivot point) of each bones (correspond to a socket on an human body) or do you move the boxes along so it lands in the middle of the bone so the box is more like a muscle. I ask that because many armatures have weird bones. Often the leg bones are close to the hips bone and so the box on the hip has to be very tiny.

I want to test some auto-ragdoll generator.

Other question :

If i rebuild my model with a more standard armature; how can i convert all my animations ? I was thinking of sticking my new armature on old, move old, then keyframing all the visual transformations on my new armature. Any plugin to do this clean ?