You may try thinking about how you would feel if you had a button that collapsed a mine in Chile if you pushed it. Would you push it on a whim just because miners dying in Chile doesn't necessarily make you sad or would you suddenly feel a personal connection to those miners by means of the button you had to control their fate?
I wouldn't push the button because
If the button painlessly killed people without relatives or friends and I were very certain that my pushing would remain undiscovered and there were some minimal reward for that, that would solve 1, 3 and 4. It's more difficult to imagine what would placate my inner deontologist who cares about 2; I don't want to stipulate memory erasing since I have no idea how I would feel after having my memory erased.
Nevertheless if the button created new miners from scratch, I wouldn't push it if there was some associated cost, no matter how low. Assuming that I had no interest in Chilean mining industry.
If it's worth saying, but not worth its own post, even in Discussion, it goes here.