My 2 cents:
Your feet jumped at me right away in that video. They were all over the place. Sometimes it appeared as if the heels might be slightly coming off the ground a bit (14 seconds in) IMO, your feet weren't set very well. The first rep it looks like your left foot actually slipped further out. The others, it seems like you're rotating your feet off your heel. Personally, I'd anchor those feet better and get that base strong so you can really spread the floor with your feet and call that PC into action.
Were those Nike Frees? I haven't squatted in those, I've always gone barefoot, so I don't know the affect the heel might have. At the least, I'd just swipe my hand over the soles right before you start. That will get ride of most of the dirt and your shoes will stick to the ground better (like you see basketball players do).
The angle wasn't one so that we could get a picture of what your back looked like. You broke parallel with each rep, but couldn't really get a picture of what your lower back was looking like. Everything seemed alright on that front, though.
Aside from that, I think you did a good job of keeping the chest up and not good morning-ing the weight up.
