Deadlift Form Check

[lohengramm14]

Hi, i got a couple of questions about my deadlift that experienced coaches here hopefully can help me with.

I am interested in start of the pull itself.
As quads are the main mover of the bar right off the floor, i was wondering if i am using them right. Are my shoulders staying in front of the bar for long enough? Am i initiating the lockout with my lower back and hips too early? Becuase sometimes i feel like i am literally using my lower back to pull and not my quads.
Once i tried to keep my shoulders in front of the bar for longer period of time and use my legs more, that felt super difficult in the lockout and i just couldnt keep the bar close to my body, so i am pretty sure that that was wrong. How do these pulls look? I am not seeing any major issues really, but i am not a coach so

Video
YouTube

[Mark Rippetoe]

These look pretty good. No major issues at all.