All have potential. Nice work.
I agree completely with all of your critics.
I've been trying my hand at street photography when I get a chance. It is the single most challenging type of photography I have encountered... and have only had two or three shots that were worth a damn.
Here are a couple...
I'll critic my own picture above, because I'm ashamed of myself for not getting a better pic. Mind you the photo quality is due to using a simple canon P&S that I keep in the chest pocket of my moto jacket.
The distractions in the photo, the people walking down the street... had I waited another 15 seconds they would have been passed the frame. I also just point and shot from a standing level. It would have been much better had I move a little to the left and knelt down showing more of the architecture and his parents. Would have been even better had the cars not been in the background.
But, on the flip side, there is a human aspect to street photos. It would have been very difficult to get any different of a photo. The dad became upset when I snapped the above pic. He didn't ask for money, but wasn't happy that I didn't ask permission first.
Think. Frame. Shoot.