Thank you very much! to answer these:
Outlines vs. No outline:
I've been thinking about it, and it definitely makes sense to add an outline to Air. I was thinking about using a color slightly darker than the current darkest to outline.
proportion and style clash: air is supposed to seem light while earth should be very intimidating; this ties into their roles in-game. Air is an offensive class that you will likely encounter on the front lines, while earth is supposed to be a defender and should make you run in fear

I will work on these.
Generic weapons: I wasn't sure on the direction that I was going to take on this, and what I decided on was to make them start with some very generic weapons and gain some more 'interesting' ones as you go on. Now that you mention it, I agree that the names of the classes should extend to more than just their appearance alone

Coloring and Anatomy: I will work on adjusting the hues, it honestly wasn't something I was thinking about at the time, but looking back, should have been more of a priority. Anatomy is definitely not a strong point for me, and there is plenty of room for improvement.
I will work on concepts for weapons and appearance ( and enlist my artsy sister for help, haha) and post some concepts here. Thanks for the help!
here is the current running animation for Air:

I used the running tutorial that has been posted in other topics several times

EDIT: possibly the new shotgun?