How could anyone think she was "innocent" of acting against the Empire, when we saw her put the plans in Artoo? That was no ATM card! A little early in the film to be running off to the bathroom and miss that detail. ;)

I've understood for a long time her "accent" was her senate/diplomatic tone of voice. It's her position in the senate that allowed her to travel to many places without attracting undue attention, hence Vader's line, "You weren't on any mercy mission this time."

In the real world, when royals serve in the military, how are they addressed, by title or rank?