On the overhead squat, for me to truly judge, the camera angle needs to be better. It should be in line with the hips, and it looks a little forward, but it could be the angle. Camera should be straight in from the side.
If at first it feels like you are going to drop the bar in back of you, it is probably correct. It is very important to arch in the bottom. This recruits the hamstrings, and allows them to assist in the drive out of the hole.