I'm not sure why anyone would think the guy is a stalker or rapist. It seems like someone said that at some point, and everyone went on with it.
The guy almost sounded like a gentleman who truly loves Lady Boyle when he talked to Corvo. Not to mention the random Boyle woman will have a letter from him in her chambers, with the skeleton key for Dunwall Tower, implying she knows him and may even actually feels something for the guy too. It is written down somewhere ( in her journal maybe ) that she is only using the Lord Regent and doesn't love him at all. Corruption by six, indeed.
The Outsider tells us she will live a long life, but he doesn't tell if this will be a happy or unhappy life. Only sure thing is that she will very probably to live this life in reclusion, as this is her "last party".
I think she got a nice smooth exit from the story, but then again we aren't led to believe she took any part in Corvo's downfall. Rather in the Lord Regent's rise, which was the next step.
Campbell's fate was very deserved, as he is, simply put, a damn coldhearted bastard who doesn't give a crap about the cult he is leading. Just ask the Heart

It's, like, the local Borgia.
The twins are corrupted, and I felt being given a taste of what they inflict to other people each day was a well-found move.
The Lord Regent is thrown in jail, but that's about it as far as we know. He'd deserved to be judged and hanged by the mob, but somehow it'd be a sweet ending for him. He is the guy that probably gets the easiest time... Or maybe not. That's the point : the bastard who did all this to us, planning everything from the beginning, and releasing the plague on the people, goes to jail and will be judged or something. Felt a bit anticlimatic, especially when his "tools" gets a much less desirable fate.
...Sorry for Campbell? Really? After all the [censored] he did to you, after all the stuff he caused, after what the Overseers do as an organization and their practices? What note are you walking about, exactly, because the ones -I- found only implied he kills prosttutes after he's done with them and supposedly molested or tried to molest Emily. So after all that, was a bit hard to JUST brand him for me, to be honest, but true, in his case, death is too easy.
I think he was refering to the note you find near his "weeper" form where he curses Corvo for what he did to him
