I have a 500 lb deadlift at 181 lbs. That's not spectacular, but I do know something about it.
First of all, put down your protractor and compass and stop analyzing it to death. The deadlift is technically speaking the simplest of the 3 lifts.
There are two dilemmas that I have noticed, watching many deadlifters. If you are too far "over" the bar at the start and not far enough "back" then you most likely will have trouble with the lockout portion of the lift. If you are too far "back" at the start and not far enough "over" the bar, then you probably will have trouble out of the hole.
So in a nutshell, there is no one right way to do it. My biomechanics are way different from yours, and Dave Tate's biomechanics are way different than both of ours. He wrote an article that fixes the most common problems among trainees. I'm sure he'll be the first to say that it is not a "fix-all" and that there are athletes that are exceptions to his rules.
I will say that your posterior chain is of utmost importance. I have taken 6-8 week (or more) breaks from deadlifting, and when I resumed, my deadlift had gone up. Train your hamstrings and low back hard. Squat heavy.
As far as the actual execution of the lift, it is hard to tell without seeing you lift. PULL HARD, and pull back. Drive your head and neck back into your traps, and keep your back arched.