limb kits is a really good idea mogwa.  like replace body part with prop, except another body part with different rigging. would be really cool if the replacement of the part could be animated. 

i also think a lot of this could be cleared up if we could animate the joint parameters, like sliding the zones and the joints around as we need them.  unfortunately no keys for them : (

the limb kit idea could make that sorta possible though.  just same limbs with the different parameters, switch out as needed.  wouldn't be a smooth, but would probably work pretty well i think.  i never did a replacement though...does the joint that was there insist on being the same? 

another possibility could be that the body parts are actually always there, but are hidden until needed.

maybe the switch in geometry could be handled the same way the "genitals" morph is.  actually i guess that probably is not animateable either though....so would have to be transparency.

good ponderings on matters that bug the h@$$ out of all of us.