For #2 I'm not sure, sorry. You could always try copying the files across, but unfortunately I doubt it will work. The anim files are very specific to the grunt's skeleton, so unless the human corpse has the same skeleton as the grunt, there is a very slim (if any) chance it will work
There are a couple of workarounds:
- either open the corpse in maya, unbind and delete the skeleton, then import the grunt skeleton and smooth bind skin. Then you
should be able to use the grunts animation files, however I think it's more likely that you will have to individually import and bind each of the animations using the anim import/export plugin for maya.
- You make the animations yourself, It's a very tedious job, and is even harder to get it looking good.