Ledging animation, Ref Pose, Root bone


I am working on ledging animation.
I create hang_idle, climbing_tocrouch animation seperately then I use animation montage for climbing_tocrouch animation.
The thing is when I set ref_pose, climbing_tocrouch turn weird like rotating the character in wrong angle.

I have three questions.

  1. Where should the root bone be located? I set it a bit off the ground according to some tutorial video.

  2. Is there specific way of creating a root bone in max?

  3. The default ref pose of character is idle standing pose. Should I have different ref pose of climbing_to crouch animation like hanging?

If you have any idea of any of those, please help me to solve this.