Re: Trap Bar DeadLift Form
To me it looks like your lower back is rounding outwards at the start of the lift. I beliebe it's not a good sign that this happends already with the modest weight you use in the videos.
I think you would benefit alot from doing direct work for the glutes, and focus on one-legged exercises until you get the hip strength to do bilateral lifts without lower back rounding. I have just started doing single leg exercises myself and, well, it's *not* easy :-P
And maybe do some mobility work so it becomes easier to sit down far enough to be able to start the lift with a concave back.