Very interesting post, Darth Asshole... I must admit I agree with you in many points, such as the fact that if we give Lucas too much control - or input - over the movie, we risk a flop. Over the years I've changed my opinion from "George is a Genius" to "George was so damn lucky back in 1970s". The more I learned about how the movies were created, the more convinced I am. It appears that the creative input done by other talented people, who worked on these movies could - if we sum everything up - be decisive factor that lead to their success. I'm not saying that Lucas wasn't needed at all - hey, give the man some credit he deserves - but the point is that he seemed to have a lot of luck to have those people working with him, rather than having the whole thing (I mean plot, dialogues, etc.) laid out neatly in his imagination. Even the fact that Ford changed few lines "in the last moment" proves that OT wasn't made exactly as Lucas could have planned ("Everything proceeds as I have forseen"), but in several cases pure luck decided that these ad hoc changes were the right thing needed.
In the case of Prequels there was far less improvisation. The technology allowed George to execute most of the things he wanted, and this also meant he had even more control, I'd say even more than during making of ANH. If you read the first drafts for OT, you will see that a lot was changed over the time and many of these changes are thanks to the members of the crew - another proof we can't say he had everything planned from the beginning. Some of these changes were forced by technology limitations in those times.

BTW: Darth Asshole, are you by chance related to Major Asshole, from Spaceball One?

Hail Skroob!