Great, some good points,
Likely, what I will do is use this, perhaps composite the scene (figure with alpha, and a separately rendered animated backdrop) since I'm not worried too much about showing below the knees.

With exporting the bvh and importing it into Carrara:
I had some other bvh files and tried them out but I'm a little confused on how they are attached to a figure, are they drag dropped on the "model" portion of the figure like hair?
I also had one funny instance where I imported the bvh and had this mini-bone-skeleton roaming invisibly around the scene, unattached from my figure, I likely had dropped in on the wrong spot.
I believe the bvh's were not consistent with naming as some trials resulted in the figure twisting wildly.
Or this may be the rag-doll effect you are indicating.
Thanks for the info so far, I'll see what I can do here...

Carrara 7 Pro, Anime Studio Pro 8, Hexagon 2.5, Zbrush 4.6, trueSpace 7.6, and Corel Draw X3. Manga Studio 4EX, Open Canvas 5, WACOM Cintiq 12WX User