I spent 8 hours attempting to improve on some of the mistakes in my pervious mesh. Specifically, focusing on the upper body. The pose is a more traditional A-Pose, the shoulders and the upper arms are much improved both in visuals and in animatability. I normalized the quads on the body a little better too.
You can see improvements in the shoulders and kicks (especially on the inner legs) as well as improvements to the armpits at full arm extension. The crotch continues to be problematic, as well as the waist. I think I need to make the groin shorter and the upper thighs extend further up the torso rather than the sharp split I have currently.
Here you can see some frame comparisons of the two meshes in the same pose:
Check out that right wrist and the left shoulder.
Oh man, look at those hips! Neither are very good but I was able to make a marked improvement. I also prefer the new shoulder, and the changes to the crotch are improved here as well. The wrist, as well, is not suffering from the same intense collapse.
Definitely improvement, but I really need to come up with better geometry for the crotch.