While the Tarkin cgi was somewhat distracting and plastic I understood the decision. Likely Disney will do what Lucas himself chose to do with the original films and replace/update the effects as better technology presents itself in the future. Tarkin's absence from Rogue One would not have made sense.

As for the question of Leia's character, here's another article:

What Will Carrie Fisher’s Death Mean For ‘Star Wars’ Episodes 8 And 9?

http://www.inquisitr.com/3832412/what-wi...isode-8-9/