1. Stance looks a bit wide. Slightly narrower stance, toes pointed out a little more, and shove knees out to match toe angle.
2. get some lifting shoes - you can see your feet lose solid articulation with the floor during the squat.
3. Your knees punch forward in quite a pronounced way at the bottom. Get your knee forward position set by the time you're halfway down or so, and then just sit back/lean over to get the rest of the way down to below parallel.