One thing about soccer or football there always seems to be good facial shoots to get because of the hard work and energy they put into the game. You did nice job of capturing those expressions. I really like how you captured second shot. So did it end up being a header:crazy: or kicked ball (Head)?
I agree with Chris on #1
#2 surely the ref's got to be whistling up for dangerous play with a boot up around her head like that? I'm not so worried about the lady in the background, looks easy to desaturate or even crop out.
#3 the focus looks odd, was this cropped from the right edge of the image?
I'd definitely try to level it, but I'm not sure where vertical is in this one.
You can't always get a clean background, particularly in what looks like a park game.
Your choice to use a long lens and narrow depth of field definitely helps with the cluttered background, I didn't notice the cars in #4 for a while because the action was good and sharp.