Looks like you're losing back extension in the squat. Weightlifting shoes, or sliding a plate under each foot might help.
Avoid hyper-extending the neck while squatting, keep a straight line from the top of the head to the hips. Don't look in the mirror, look down into the corner.
Flex the wrists, or at least keep them neutral while keeping the bar racked in the groove. They're hyper-extending right now. Try a narrower grip, which will help tighten your upper back a bit more.
Knees look like they're moving around at the bottom, keep them out to the side. Be sure to go over how the low bar back squat feels at the bottom sans bar.
Try a slightly wider stance, and turn your toes out a little more than you think you should. Are those squishy soled shoes?
Find your "bounce."
Tighten your lower body before pressing, avoid push pressing.
Deadlifts and power cleans: stance and grip looks real narrow.
For setup purposes
1. Place bar over midfoot, most likely where your shoe laces are
2. Bend at hips, and get your grip set
3. Push shins into bar, without moving bar out of position
4. Big breath, and lift the chest
5. Pick up weight
Get shoes that allow for more efficient force transfer. Running shoes aren't good for that.