BigPurpleSkiSuitIt's simple math. You know how it's hard to hold a weight farther away from your body? Your jointes have to work harder for the same reason the taller you get.
wrong vector for torque. (Picture a skier standing frontside and place the middle of the feet as 0,0 on a Cartesian plane) Your using a Y axis in your example when you should be using an X vector. Unless your talking about flips, height has nothing to do with torque. Having a beer gut will influence the X axis vector.
Weight would be the correct answer. Mass being decelerated is the killer in sports. Heavier people have more force being applied to the joints when they decelerate (crash). Flexibility extends the range something will bend before they break. I would bring the physical shape into the account. If you have great cartilage and the body absorbs the right amount of nutriments to maintain it, injuries are far less frequent.
An abnormal center of gravity is of cause of concern in theory, but in practice; it has nothing to do with overall performance. We get used to the center of gravity and adjust ourselves automatically. It does get screwed a little during adolescence because of the growth spurt and the rapid weight gain. However, this get corrected 2 years later. Seen it from ages of 12 to 16 in guys when I was coaching.