http://www.fastswf.com/K84GYGo
1. first time animating without guides
2. haven't been animating normally like I would be
3. i am aware of the resizing

The limbs are pretty stiff. Give that torso a little more backbone and bending. The punch was sudden and seemed a little rush. Take your time to see where the limbs can flow into a punch and ease out into their next movement. Sometimes when I'm focusing on more movement with legs, I'll animate the arms last, and vice versa. Try focusing on each limb having their own movement and flow my friend!

The first kick doesn't look like it has enough force to kick somebody's ass. Maybe because you added the 'trail' late.

See how different it might look when the trail starts riiiiiiiiiiiiiiiight when he's about to kick (meaning, when he's about to lift his leg).

Also, see if removing some frames between the point where his leg is ready for the first kick and when his leg has already kicked gives the required 'speed' for his kick. Because kicks are fast and badass.

Double frame. Double frame. Do double framing to get that 'impact' for the kick.

Hopefully you know how to double frame. If not, get some kind of idea from here: http://forums.stickpage.com/showthread.php?1000-How-to-Double-Frame-Pivot-Movements
(yes its for pivot but you get the point)

The kick is bad because there is no follow through with it. If the poses were better, the kick would look better.