I like 78, 94 and 27 the best. (27 was me sitting, right?)I think you do a great job on details, like really capturing my shoes in 27, and you do well with faces also, I think your area of improvement should be in basic proportion and flow/movement of characters. I recommend you forego the details and draw as basic as you can, doing what Jasmine does already. Get the very basic form, breaking things down to shapes. I know you will want to add detail, which is fine, as long as you get the basic shapes right. Also, you should do the basic shapes in pencil and then finish in pen. I can't wait to see the results.
I really like that you took an entire page to practice with the different faces and proportions. I agree with Mike that it would be a good idea to practice basic shapes and get the proportions of the body right, along with the motions.