SQ: You can likely fix your butt wink by cleaning up your form. Take a big breath and bear down with your abs to keep your back flat. Keep it flat as you go down (don't pull up with your chest as it will arch your back). About halfway down your knees should not go forward anymore and you need to reach back with your butt. Then stop just below parallel (you are too deep). Try doing all this and pushing your knees out hard in the bottom.
DL: Keep the steps separate: setup, eyes, breath and squeeze, pull. Once you setup, lock your setup in place. Don't let your hips drop as you squeeze your back (they knock the bar forward when they drop). Squeeze your back harder/flatter. Keep the bar close as you pull and as you pull, don't pull with your head/neck. Keep it neutral looking at a spot on the ground the entire time.