I can tell little from this video angle but what I see is:
- your lower back is probably fine; it might round very slightly, but this will go away when you fix other things in your form
- your depth is good in those two reps
- you sit back with the hips fine, but you do it to the point where your weight is too far back on the heels
- you need to focus on keeping the weight over the mid-foot; this requires that your knees go forward more at the beginning of the squat; hips and knees need to initiate the movement simultaneously (not hips first!); hips begin to lead after the knees have established a position very slightly in front of the toes
From what I can tell there is nothing physical hindering you to learn to squat correctly. Lance has a pretty similar idea about a good squat as me from what I can tell. So listening to him is a good idea. Listening to everyone at once is a bad idea, since some people have a very different definition of a good squat (not always a sensible one).
