I think the key problem with the Stormtroopers is the helmet. I think it's a little too large for the body, and it's too squared off at the bottom. It needs to be smaller, and tapered more. Other than that, the Stormtroopers are fine, IMO.
As for the second shot, looks to me like Kyle just cut the head off that Probe Droid. I reckon he just used saber throw to decapitate that piece of Imperial junk!
I like the pieces of debris flying off with the smoke trails. And the lightning around the Droid's body is simply superb - very reminiscent of R2 getting fried in the films...hehe...
And these are from a game only a few months old? If they do some tweaking and polishing, I think JKO is going to be a real blast!