I'd be fine with the show itself just keeling over and dying.
The people responsible for this show have no idea how to do a slow, deep, thought-provoking series. Killing off characters, especially for the purpose of introducing new ones, won't change the fundamental problem with the show. I'm sure most of the actors aren't all that bad -- its the writing, direction, and style of the show that needs to die and be replaced. If I had to work in those conditions, I doubt I'd be an interesting, let alone entertaining, person either.
Just look at Robert Carlyle. He's not a slouch of an actor, and despite doing the best he can given the shit he has to work with and the only character with any interesting traits and background to speak of, even Rush comes across as mindnumbingly dull.