The gestures look really good here. Nice flow to the figures, plenty of action and expression.
I don't think head placement is a problem, more size. The head is consistently small in relation to the rest of the body. You can of course do this for effect, but if you're feeling nervous about what the head is doing, I'd suggest doing the good old 7-head measurement both horizontally and vertically and work with that a little while. You're really not far off at all here. Beyond that, you're well on your way to larger poses and longer timeframes, so take on the occasional 30 minute study and just dive into the detail once you get the basic lines down like you have.
Best of luck!
