1.- There are 2 pairs of hands because 1 is the API that shows the output of the LeapMotion and 2 is the BVH with the movements of the API plus the options correction. if your are confused, you can change the .OBJ file of resources/objects/bone.obj. It must have a texture and be triangularized.
2 The inclusion of objects with physics can be done but it would slow down the process a lot.
3 It could be done, it is more I have thought about it but I like it more so, I do not know the Blender so deep or the python.
4 It is created with the Save config button.
Thanks for the comments.
(Thanks to bing translator) :)