A few interesting bits from http://www.starwarsnewsnet.com/2016/07/rogue-one-a-star-wars-story-costumes-panel.html ;
“Jones says that Jyn knows who she is and where she comes from, which sets her apart from previous Star Wars protagonists, and she is more seasoned as a character.”
“Luna’s character, Cassian Andor, is the second member of the “Rogue” team and the de facto leader. His only friend, K2-SO, is a reprogrammed Imperial Battle Droid.”
“Tudyk shows K2-SO as the comic relief of the film, and notes that the motion-capture process was important to bring his character to life. He’s described as being “not all there” and brutally honest due to his imperfect reprogramming.”
“Edwards explains that he wanted to film a scene in a subway station due to its futuristic look. The sequence was filmed in its entirety in the four hours that the station was closed.”
“Whitaker’s Saw Gerrera is an extremist guerilla fighter. Whitaker notes that he has seen the episodes of The Clone Wars that feature his character.”
(I previously assumed that the RO connection to the Clone Wars series was kind of tacked on, but I guess they might have put some effort into it?)
“George Lucas visited the set of Rogue One, to the surprise of Edwards.”
“Mads Mikkelsen’s Galen Erso is Jyn’s father and “a person of interest”. He was a scientist that invented something so beautiful that would change the world.”
“Mendelsohn explains that Krennic is a different kind of villain in the sense that he’s smarter than many of his predecessors and more inventive.”
“Darth Vader is confirmed to be in Rogue One yet again. James Earl Jones is reprising his role.”