I don't think it'd be wise for Iran to strike Turkey, as then they'd only add another enemy to the list. Even if the strike is aimed at NATO, if it happens on Turkish territory, it would be seen as an act of war. Turkey is at odds with Israel in certain respects, so you'd lose that leverage as well.
As for the nuclear issue: Israel acquired their weapons in the late 60's, a time when large-scale warfare was indeed a reality for them. Countries scrambled to get the most powerful weapons possible, although more as deterrents I would say, not with the outright intention of instigating outright nuclear war. It's like a dog that gets cornered and shows its teeth as a warning, saying "back off or you get these..." I don't think they'll let their weapons go soon, perhaps reasoning that they need the fallback option in case something drastic happens.
I also think it would be best for Iran not to acquire nuclear capability, and people equating their plight with that of Israel is a false equivalence, I think. No one is threatening to invade or obliterate Iran, whereas Israel enjoy no such assurances. Israel is threatening to strategically strike potential WMD developments, not to nuke Tehran.
As others have said, Iran signed the non-proliferation treaty, so if you sign the treaty then abide by the rules. Although I think their options are quite limited at this point, as backing out of the treaty would almost certainly be perceived as them wanting to develop nuclear weapons, even if that isn't the case.
It's also a little disingenuous to pretend that only the West and Israel are opposed to a nuclear Iran. The rest of the Arab states have much to fear, although they wouldn't make it so clear in public, being happy to let the West and Israel take the heat.