Including some of those characters was a necessity. Jimmy Smits/Bail Organa financed the rebellion (and it's not like he had a lot to do in Ep. 2 & 3). The Moff Tarkin stuff only sucked because the CGI was bad (I do agree they could have reduced the "role"). "Leia" was on the screens for maybe two seconds, and I thought her sole line fit perfectly with the theme of the movie. The only thing that didn't work was the R2/C3PO cameo, but I'm willing to cut that a little slack because they've always said that those two characters are going to be the only constants. The fact they were in the movie wasn't bad, but it could have been done in a way where it didn't seem stapled on after the fact.

But the overall point is that ***all*** of these Stars Wars supplementary stories that they currently have planned are going to have "fan service" to some degree, because they all relate to the stories that are already the cornerstones of the entire universe. I mean, the next three of these are going to be Han Solo, Boba Fett, and Yoda origin stories. I imagine there will come a time where they will be able to tell entirely new stories with all new characters in these films (if nothing else, after the third trilogy is over), but to expect these films to exclude the past Star Wars history is going to be an exercise is futility. As long as the cameos are done well, I don't care.