I think all of these are absolutely wonderful. As far as the line quality is concerned the more of these that you do the better you’ll get at describing a contour with one single line rather than a whole bunch. If you want to Improve faster I would suggest doing the entire set over again but this time try to describe each contour with one single line. Every time you put down your pencil on the page have a plan for where you want the line to go and how you want to look like before you do it. Then execute it once. this is a great way to get out of the comfort zone of trying multiple lines consistently just to try and get the proportions correct. The idea is to bring some intentionality to everything you do on the page.

Hey ! I think your opinion is correct, main thing is the quality of the line, i'ts a really common thing with students ( wich I am too obviously so take these advices with a grain of salt :) ) You should focus on using less lines, because yeah, on some of them, I can see " the right line " but it's sometimes clouded by others close to it. For example the upper arm and lower arm included can be described with 4 or even 2 lines sometimes. "Pretty much all them has too much detail for this exercise" I don't fully agree with " pretty much all " but yeah, sometimes you're thinking too much about drawing the muscle and every form, wich can damage the gesture. Also, try to take some male reference maybe ? I understand that female references tend to have more "pleasing " and flowy poses, but a bit of diversity can help :) Ps : Picture number 5 , left page and top right, I think you really nailed this one, well done ! Pss: You inspired me to take a look at my old gesture drawings, I can apply the same advices I just gave you actually :D You inspired me to get back to gesture ! Anyway, I hope it helps !