You could make it with only 1 button, (your first) and it could still end up doing the second. Full extermination of the people vulnerable to disease and hunger is, in fact, a valid optimization strategy.
There is no getting around the fact that these things are nothing like regular technology where you can at least decompose it down to functional working parts. It isn't debuggable basically. Nor predictable.
Maybe it’s a bad idea to put powerful tools in the hands of people you know will misuse it.
Let‘s make e gedanken experiment.
We create mighty tools with two buttons. Button 1 solve world hunger and cure every disease. Button 2 kill everybody but you.
Would give everyone such a tool?