For squats, your knees come a little too far forward. I suspect that driving them out better will largely correct this. You also overextend your spine on the ascent. Keep your abs tight as you drive your hips up.
For deads, your hips should be higher and you need to squeeze your chest up until your back is flat. Check the sticky at the top of this forum for help with that. Are those plates smaller in diameter than normal Olympic plates?