These issues are all because of the same problem; the bar probably isn't in the right spot and you're not keeping your chest up. Lift your chest up hard before you descend and KEEP that position even as you bend over.
Your hands are too high on the bar. The wrists should be straight and hands pressed against the bar, not on top of it. It looks like your hands are sitting on top of the bar with a bit of wrist over extension.
What's happening is that the bar is rolling forward so you're hesitating to drive your hips for fear that the bar will roll up, and as a result you're lifting your chin to try to keep the bar in place. At the same time, you're using your hands to hold the bar in place, and your elbows are getting part of the load.