Red Superfly
You creepy little stalker
Vader was NOT the central character when Lucas wrote ANY version of of ANH. Vader changed through many drafts of Star Wars - but he NEVER was the main character. Also, the whole thing about Vader being Luke's father wasn't made up until they were making ESB. As far as Lucas saying it's all about Vader - that is true NOW. Back in 1977 - the main characters were R2D2 and C3PO or Luke and Han. Vader was way down the list. He was just a baddie who killed the goodies. In no draft is Vader a deep character. Vader was a lackey for Tarkin, and Tarkin was Emperors lackey, nothing more, when ANH went to print.
Even when Vader is elaborated upon in ESB and ROTJ, which turn him into a pivotal character - with the sequels revealling Vader to be the second in command, and that he was on par with Tarkin, not below him. He is given this depth post-ANH, yes, but Luke Skywalker is the main character of the OT - he always has been.
Its crazy how Lucas keeps insisting that Vader is the main character - thats very weak minded of him. Vader evolved - and how the character panned out was down to chance (many argue everything about Vaders genius as a character was pure accident on Lucas' part - I also believe this). A lot of Vader's character was a result of artists and Ben Burtt's sound effects - Vader's story evolved from his demeanor in ANH - NOT from some sort of amazing idea Lucas had.
He's saying "I want everyone to think my entire series is based on this coincidental, flukilly interesting character that I came up with almost by accident". I wouldn't be proud of my movies if made them like that.
Vader being part of Lucas' original vision is BS. Why would he accept an incidental character as the main one of his whole series? Luke is the main character of the OT - Anakin/Vader is the main character of the PT. To say Vader is the main character of them all is absolute twoddle and proves how Lucas doesn't even know what his original vision is supposed to be.