First of all, I'm loving the curvature you're getting, very expressive, shows looseness.
If you're going for gestures, I'd recommend disregarding proportions entirely for your first draft, as you don't need to focus on that for now, you can always draft it again, pull things back and forth and really play around with it. I've learned that gestures are really fun to mess with because you can really be loose and free flowing with it, and you can stretch things out as far as you can take it. :)
I'd recommend first not worrying about finishing the subject as you need to be looking at the force and the flow of it. You can capture a lot of that in the core or the torso, and build out to where the force and weight is distributed. Once you start getting that, you can draft it until you see fit or you can focus on a single image on a longer timer and just draft that over and over again. It's a great way to really grind that understanding. If you need a better explanaition, as I'm not a master myself, you can always look at Kienan Lafferty, host of the KNKL show as he talks a lot about flow and really breaks it down, or look at Aaron Blaise, he collaborated with disney and his animations really show the weight of the images he makes, and he breaks it down rather well. There's also some books, Force Dynamic life drawing for animators which is a great visual aid as well
I love those drawings you've drawn, simmh. I really don't see anything wrong with the gestures and proportions, but, I've got one small request: Why don't you go for yet another 4 minutes of 30 second sketches, followed by 10 more 29 second figure studies, pretty please? The reason why is because, your line quality will be more than improved and refined, in terms of motion. Hope and pray that it'll work out for you.