No idea on the back rounding. I would say that it would be better for you to develop your style of deadlifting FIRST and THEN attempt form critiques. How you pull with running shoes is going to be different from how you pull with chucks/socks, so trying to critique THIS form isn't going to do a whole lot for you.
In regards to making sure the bar is even, I would personally make sure the bar is even, then stand back up, and THEN deadlift. I find that spending too much time in the bottom position kills any sort of leg drive/explosiveness off the floor.