I don't think he trashes it or says it "sucks." He says it was "mediocre" until the Third Act and then it kicks ass, which isn't an unfair description. I'm aware of what A New Hope must have seemed like to audiences used to campy 50s, 60s, and 70s sci-fi, but that context doesn't matter much nowadays.
Definitely a good instance of the "Western in space" subgenre. Though, to be fair, some of the effects during that sequence are distractingly bad. They just used whatever Halloween mask they could find.
True on Leia.
With only A New Hope to go on, Vader isn't a particularly memorable character. Many of the best bad guy moments go to Tarkin holding Vader's leash. Most of his legend is built in Empire and Jedi.
Dear goodness don't give Disney any ideas.
I've always joked to myself that Star Wars is basically an AI prompt that reads...
"Come up with a science fiction movie based on Dune only simplify the plot for a more general audience, change enough to make it a distinct IP and thus avoid a lawsuit, and make the action sequences cool and based on what the filming and special effects techniques of the late 1970s can handle. More or less cribbing from WWII dogfight movies could work. Could we make that sort of thing space-y enough?"
