This is excellent, and a much needed reminder to be very afraid of the Doctor.
You know, those of us who have followed the Doctor's story for, well, donkey's years, know that s/he is, at heart, terribly ambiguous when it comes to operational morality. Oh, the big picture, black/white questions are generally resolved on a good vs bad axis (fixed points notwithstanding) that we can feel good about, but there are other things, the gray, shadowy things... the times when the tossed coin lands on its edge (or in another universe) and when the temptation to use a reset button must purely scream!
The Doctor, it must be remembered, has always walked among those shadows.
Author's Response: Yeah, it appeals to me a lot that there's a certain moral ambiguity under all that goodness!