I think for the drawing in the middle, the pose is a bit off-balance as the center of mass isn't above the straightened leg. Also, the head is a bit big. Overall, I think you got the gesture down pretty well but it would be better if you really showed which parts are being stretched and which are compressed by using more decisive curves, for example, the left side of the third drawing could've just been drawn with one c curve. Another example is on the right side of the hips on the first drawing, you drew an awkward bump that goes against the gesture. Also for gesture studies, don't focus on the details and shading and try to do them as quickly as possible. Don't rush learning anatomy yet and make sure you can draw accurate proportions first. I hope this helped!

I think you could blend out the hard edge on his butt to merge the shadow with the background.

Nice job! I really like the shading on this portrait, and I think it conveys the form really well. I also struggle with proportions and don't notice big mistakes until too late. I found that taking breaks while drawing and looking at your drawing from far away sometimes can help you find these mistakes. Also, double-check that everything is correct before adding any details, cuz afterward you'd be more reluctant to erase things lol

I think the reason it's not aligned with the 3d model is that in the first step, you drew the centerline a bit skewed. If you take a look at the vertical line on the "cut out" portion in step 1, it's not parallel to the line you drew. Also, as a side note, the actual pelvis looks like an ellipse when viewed from the top. I think Stan mentioned this in the critique video. The wider this ellipse is, the more the top plane would align with the blue line you drew.