Most of that isn't true. When I lived in California, you simply asserted that your name was X, where X is someone on the list, and you got X's ballot. No need to know their address.
If they already voted? "Oops, I forgot."
If they haven't voted and come in later, so what? You're long gone.
I can see that happening maybe a few times, but it seems ineffective on a large scale.