Man, there were a few things I wanted to bring up about this movie, but I think you got to most of them before me (and more eloquently too). This really is the movie where Darth Vader comes into his own. I was trying to remember Star Wars, and I don't think he actually kills anyone in that movie, except maybe the rebel who he strangles at the start of the film. Compare that to Empire where he goes through admirals at an alarming pace — and they're his own admirals this time.

You also mentioned Grand Moff Tarkin having reined him in. Their relationship is probably one of the more interesting ones in the series. Tarkin seems to be one of two people who can boss Vader around — the other is the Emperor, who Vader is clearly very subservient to. But Tarkin and Vader talk like equals — like old friends. I think Tarkin actually calls him "my friend" at one point. I've always been curious about those two because it seems like there's a lot of history between them that we don't get told.

I noticed something this time around in Empire, though. When R2D2 talks to Luke on the way to Dagobah, his beeps get translated for Luke on a little screen — we can see the alien characters scroll by. Then I realized for a series of big movies, there's almost no signage in them. That's pretty unusual when you stop and think about it because written words and signage can convey so much without exposition. There must have been a conscious design decision to leave out any writing. I asked a friend about this and he mentioned that the one example of English writing he could remember (on the controls of the tractor beam in Star Wars) was replaced with alien characters in the special edition.