Hi Tom. This is looking so great and you have a solid collection of sketches to work from. It's pretty cool that you are doing a whole bunch of them before you start painting. Seems like a pretty good way to work.
I'd say if you took them to finish as is, they would all be great. I do have a suggestion on where I feel you could improve as a whole- and that is with exaggerating your gestures a bit. This is perhaps a personal preference, but I think you could nudge your gestures a tad more to really illustrate the feeling of each character.
I've manipulated your images to hopefully illustrate what I'm talking about. I mainly used liquify, so they may look a bit distorted.
Thanks for sharing these, and I'm very excited to see these come together as finished pieces.