They should have just left Tarkin and Leia and others out of the equation. The technology just isn't there. They're not fooling anyone. It's completely immersion breaking, especially for someone who knows those faces and voices by heart. Leia was the worst, as it's essentially the last thing you see before the credits roll. Also, let us use our imagination. We don't need to see Leia receive the plans by hand and then blast off into hyperspace on Tantive IV. We can put two and two together.
I get that it's a prequel, but the filmmakers aren't doing themselves any favors by trading in nostalgia at the expense of the here and now. Rogue One was a chance to expand the Star Wars universe. By remaining so dependent on Episodes III and IV, it felt more like a contraction.
I know you posted this a couple of days ago but I only just seen the movie today and while I pretty much always agree with you or think alike, I got to disagree on this Veknoid.
Governor Tarkin was vital to have in this movie. Tarkin is the big man in the Empire's Death Star program. You see him at the start of it at the end of Episode III and obviously he runs it in Episode IV. It would be weird if he was absent now; being the man that started it to being absent to being in total control again. You'd wonder where he is and what he's doing instead that's supposedly more important and how he got back in full control like a day later considering this movie ends pretty much where IV starts. Cutting out Tarkin would mean having to cut any Death Star scene for it to make sense and for it to avoid complicated questions. Besides, they couldn't have done a better job with it. Personally I was totally shocked and confused because I didn't expect him to turn around in his intro-scene because I knew Peter Cushing's been dead for like 30 years. "Peter Cushing's really in here, what, how?" lol. Obviously though because he's a pretty sizeable role you'll see more and more imperfections and see he's CG, but like I said, that wasn't distracting in any way and they did an amazing job. Makes Arnold in Terminator Salvation look like a blow-up doll.
And as a side-note, I didn't mind Vader's pun either. He's always been a bit of a smart-ass, and has one-liners in every movie.