I got curious and tried padding up to 36d out of curiousity
since I am naturally barely b. No hitting at all. I guess I have a longer torso or something(5'8").
The much earlier refference to crank length is to extend or reduce leg stroke. The longer the arm, the more your knee will come up on the up stroke.
As far as the other pain, saddle tilt is very sensitive and critical to help that. On my road setup I have to have the saddle almost tilted forward to keep my pelvis at the right angle. On the MTB it is almost tilted back.
Ride it, break it, fixit, ride it...