Avik,
The Iranians do have missiles that can reach Israel as do Egypt, Syria, Jordan and more countries in the area that would be more then happy to see Israel gone. They don’t attack because strategically the benefits of not attacking are stronger and attacking would be suicide.
Obviously a prerequisite to them having a state would be their recognition of Israel. In their own state they will choose their leaders for better or for worse. It wouldn’t be Israel’s problem any longer. They can do what they want in their country and if they mess with their much more powerful neighbor, well then they will get decimated. A combination of presenting the strong benefits of economic cooperation and strong downsides of attacking would be a powerful incentive to make it work.