The only thing stopping Israel from doing that is international outrage. Israel is entirely dependent on its benefactor states like the US and, while it pushes the limits to the extreme, must at least contend with world opinion.

You seem to be ignoring the retaliation that would be enacted at a drop of a couple of those bombs.

The fact that I just spent five minutes thinking about it proves that it's not ridiculous at all. The scale is different (so far), but I’m not convinced there’s a qualitative difference.

The existence of camps where jews and other "undesirables" were kept for long periods of time disproves this entirely. The Nazi's were not trying to speed run the process. They were systematically eliminating people. That's why it's a genocide and not a series of massacres. I would suggest sticking with the definition of genocide instead of coming up with your own convenient version.