If some other SSCs gave you programming advice, you're good to go. Your back looks fine. So, as long as you keep bracing hard like you have been you...
Yeah, you're "pre-bending over", so stop that. Just pause it at the 8 second mark and that's the start position. Pause it again at the 9 second mark...
I don't know that she hit depth at all, regardless of where the bar is relative to the toes. Stance looks too narrow and frankly the weight looks too...