Hips a little higher. you're down too low. This makes your knees be out over the bar and you have to go around them on the way up. puts you on your toes rather than on your heels. Can see your heels shift as the weight goes past the knees.
Flat shoes. Having a heel messes up the mechanics, puts you on your toes again.
By being a bit higher, the shins will be nearly vertical and so your pull will go straight up, letting you keep the bar closer to your body once past the knees. It also lets you pull equally with the back and butt while pushing with the legs.
Really tighten the glutes through the whole lift else all the force is generated by the back and that doesn't work for really heavy weight.
Dunno that you need to go down so slowly unless your gym has a policy about thumping the weights... You'll save energy for more reps. Or up slowly for that matter. Every rep should feel like you're exploding upwards. Take up tension from the bottom gradually but once off the floor, DRIVE!
You're looking up which is good and your back stays in neutral position through the lift, also good.