I guess that step 4 is probably incomputable. The human body is far, far too complex to model exactly, and you have to consider the effect of your weapon on every single variation on the human body, including their environment, etc, ensuring 100% success rate on everyone. I would guess that this is too much variation to effectively search through from first principles.
You don’t need to do any fancy computations to kill everyone, if you come so far that you have nanotech. You just use your nanotech to emulate good old biology and synthetize well-known botulotoxin in bloodstream, death rate 100%.
The main problem here is:
You don’t need to do any fancy computations to kill everyone, if you come so far that you have nanotech. You just use your nanotech to emulate good old biology and synthetize well-known botulotoxin in bloodstream, death rate 100%.