New job? (Dishonored 2)

Change the question, please answer, so be it in the 8th Chapter to take the present Duke and to put the double? The game has already passed, but left a mess in my head.
Make a conclusion such that Corvo and Emily, too, are not angels, if you do a coup and kill everyone. A family demolition. And the game itself is a delusion of the artist, which allowed to create the second part.
Why did counting kills, if they do not affect the ending? Collected at the end of the rune from the skull, removed the twins Delilah put her on the throne, and the picture returned to Emily's life. It is even better to go for Corvo if Emily can spice things up. But the dlc don't give the choice to play for the man.