Greg Cosell from NFL films, who I threw some posts at you on a different thread. Cosell is sort of becoming the defacto accepted study film expert by the NFL shows. you might be interested in these links. His position doesn't perfectly dovetail yours (he for example factors supporting cast as key but also esteems the value of a QB higher in importance) but he does on a number of points -- he's a big into a QB's skill set is by a mile the key, loves Bill Walsh and thinks him being ahead of the curve helped his QBs succeed, loves Cutler, etc. Here are some excerpts from those 2 articles.
Coach Walsh always believed the play of the quarterback could be, and, in fact, had to be manipulated and managed by the passing game schematics and by extension the play-calling. You had to understand the quarterback’s physical attributes, and structure the offense, specifically the passing game, accordingly. I remember him telling me that he threw the skinny post with Dan Fouts (Walsh was the Chargers’ offensive coordinator in 1976, for one season), but not with Joe Montana. He said Montana could not make that throw very well. The overriding point was this: the passing game concepts, i.e., route combinations and reading progressions, had to maximize the quarterback’s strengths and minimize, or even eliminate, his limitations. Walsh was the first coach to apply this conceptual construct, and he forever changed the way in which coaches design pass offense.
All these traits are visible and discernible on film. They are some of the subtleties of quarterback play, the nuances demanded at the NFL level. It’s a highly disciplined craft. Critical moments in big games are not defined by random and arbitrary play. It’s tangible and quantifiable skills that most often produce the memorable plays. Eli Manning has reached the point in his development in which he has mastered many of them. Manning simply plays the position the right way. That’s the reason he performs well in the fourth quarter. It’s a function of measurable attributes that produce consistent execution over time.