Premises

Bit of a work in progress here. The idea is that the solutions change depending on which premises you pick to be true.

Premise 0: All acts are reversible

Any act can be reversed, including the destruction of humanity

Status: Unproven - don’t take this as license to destroy us all and just press undo if it doesn’t work out
Provisos: Critical information and capabilities are not irrevocably lost

This premise is an analog to but not identical to the reversibility of physical law. Even if humanity cannot be recreated after destruction, a sufficiently close approximation can in principle be created, so long as there is sufficient information remaining to guide that recreation and permissions to allow said recreation to function.