also, I think I have an understanding of the basics of joint orient from that, but I'd have to apply that a little more to be able to really understand it. It seems like it's, like you said, like having an extra control for your rotation. If I understand this right, if I had a character in a T pose, I'd want the joint orient to have 90 degrees on the z axis for the upper arm, that way the default values for the rotation are zero but the joint is still in place.
(edit: wow, 1 minute later in the video you do that exact thing)
