oorat, I like where this is going, but I think the first one is a little weak compared to the rest.
The cape cramps the motion on the character a bit, and one of the vital rules of action drawing was left out from the posing. Left hand forwards, left foot backwards. It's simple (and you used it on the other sketches), and it works.
Despite that, I want to see where you're headed with this style.
BTW, is the Kid America meant to be satyrical (like Team America)?