Oh wauw.. I don't really know, but I can guess a couple of things:
1. try to get the angle of the terrain and rotate your character a bit with the same angle. But that would be sloppy since he won't be standing upright.
2. Try to get the angle of the terrain, and based on that angle, you can know howmuch your one foot is above the terrain. I think you'll need more animations then for a few different heights.
this is rather complex, youd need to manually transform leg matrixes, in the way as it is presented in "animation\*" tutorial where the skeleton rotates his head
I have this on my todo list and I'll add a tutorial about this in the future
I have yet to see a game that does this properly. It's no easy task as it usually needs something of the likes of inverse kinematics.
It's a feature I never expected but Esenthel, if you think you can add it it would be nice