Good points. But I'm thinking that the pain of death is purely because of the loss others feel. So if I could eliminate my entire family and everyone they know (which ends up pulling essentially every person alive into the graph), painlessly and quickly, I'd do it.

The bug of scope insensitivity doesn't apply if everyone gets wiped out nicely, because then the total suffering is 0. So, for instance, grey goo taking over the world in an hour - that'd cause a spike of suffering, but then levels drop to 0, so I think it's alright. Whereas an asteroid that kills 90% of people, that'd leave a huge amount of suffering left for the survivors.

In short, the pain of one child dying is the sum of the pain others feel, not an intrinsic to that child dying. So if you shut up and multiply with everyone dying, you get 0. Right?