[paulluuk]

OP here: I don't see why you'd be downvoted for this, it's a fair point! I agree with each of your three points, and in response I'll change the requirements a bit:

How can I get 1 dollar to as many people as possible, while spending the least amount of money on transactional costs or fighting fraud/corruption?

I think all of the edge cases you named above can be dealt with given this new requirement. Some fraud and corruption will happen for sure, just like with any financial transaction anywhere in the world. I would say that fighting fraud/corruption is only worth it, if the cost of fighting it is less than what you'd lose to it if left unchecked. A dead grandma will be too expensive to disprove, but someone making thousands of fake personas must be detectable somehow, such as re-using the same bank account or adress a thousand times.