It's been damn near 10 years since you posted this, but it was a very enlightening read. I'm sorry to hear about the genius who crafted this screenplay passing on - there's no denying the film wouldn't be a classic if not for your father's contributions.
Several years after you published this review, Walter Hill came out with his "Ultimate Directors Cut" of the movie, with those comic book-style transitions and a similar intro sequence. I'm just curious - if your father were still alive, what would he have thought of this version of the film? Quite honestly, I find it quite disappointing only this directors cut is still in print (and subsequently, the only version to be released on HD video formats.) But that's just me.
Either way, I'm very sorry to hear that your father has passed on (and I know this post is VERY late, chances are you probably won't ever read it.) This film is a classic, and it's great to hear on here from someone close to a man who was so instrumental in bringing this classic story to the screen.