Skidmark - Better than I was expecting, from what you said. Good depth, back is solid, and the knees look OK from that angle (although wobbly). You are lifting 'high bar' style though, which I doubt is what stronglifts teaches for strength gains. High bar is really for Oly training since it leads to a more upright position which develops the quads more. It's also the way pretty much everyone picks up the bar at first, so don't sweat it. You are not a freak for naturally wanting to lift this way. At your weights, it doesn't make that much difference. But since damn near everyone squats for the nominal purpose of pure strength, I think everyone should be squatting 'low bar' style. I find it a much more secure position to lift from, although it will take a while to get used to it. Your arms lock the bar onto your upper back so firmly that you don't even need to use your hands to grip the bar (I don't). Once you do, you'll never go back.
Here is what you're doing, and what I think you should be aiming for ( (2) and (3) respectively - edit: oops):
Stuff on work on:
- Get your wrists forward, not bent backward.
- Neck straight - you can keep your chest up without craning your neck and head backward.
- Pick a spot on the ground about 6 feet in front of you and focus on it.
- Pick up the bar in the middle
- Go down faster - nothing to be gained by doing the eccentric portion of the lift slowly. You need the bounce that comes with rapid contraction at the bottom once the weight goes up.
- Hard to tell from the video, but you don't seem to be breathing right. You need to be holding a big breath to get the chest up and the core tight throughout the movement. This is something that will probably sort itself out once you go heavier, but get used to it now. Breathe at the top. DO NOT breathe out at the bottom.
- And don't lift in your socks on a polished wood floor! Do I have to spell it out
I don't need to tell you that at heavier weights even 1 or 2cm of deviation from the middle of the bar is going to fuck you up big-time so get used to finding your spot now. Part of your problem is that you are not getting under the bar at standing height, but I guess there is nothing you can do about that for now.
Plenty more detail here if you want:
http://startingstrength.wikia.com/wiki/FAQ:The_Lifts