The portrait is very good. It's an excellent photo. Lose the watch it's a distraction. Crop tighter and adjust the tone response. The photo is muddy and lacks contrast -- no black and no white. Like this:
I love these...brings me back about 10 years to when I used to spend every day watching Rodney Mullen and Daewon Song. I would practice 360 flips until the sun went down! Great shots.
This brings me back too. In between "official" skate shots, I would just document all the other stuff. Usually in b&w too.
My only input is that the skate shot is the weakest. You need to get some separation of the skater from the background. If you won't be lighting it, consider moving the camera to place the skater over a more contrasty background, something he will not blend in.
I use to use speedlights to light the skater, which would allow me the opportunity to underexposed the background. Thus creating great separation.