Doesn’t matter. Israel had ~400 nukes back in 2002, and it’s certainly not less now - probably 600-900. That places Israel on the same order aas the “big 5” - the US, Russia, France, Britain and China. Actually, it ranks behind only the US and Russia.
Which means that Israel has long since achieved overkill. Old term, not much used anymore. But erasing every islamic filth-hole from the face of the planet is eminently doable and might even, to the more bloodthirsty among us, be great fun.
Yes, they are. And a lot of them are "clean" devices with little radiation, in fact some rumours back in 2002 was that they had managed directional blasts. But that doesn't mean they haven't beefed up the armory with high-effect thermonukes for that kind of use, the probability that they have is quite large. Israeli military thinking has explored this a lot, see Samson option and Yoram Ettinger.
Overkill in the old-time, MAD context is the treshhold for eradication of humanity in total. The old MAD days had another, more interesting doctrine buried in all the stuff: personal targetting. Target the known location of a head of state with enough megatonnage to be sure to get him, if collateral is 100.000 dead or a million dead.