Yeah, and jews have lived peacefully on Palestine for a while prior to zionism, the destruction of the Jewish state doesn't mean an end to jews living in Palestine.

This is assuming that you think "destruction of israel" means destruction of the apartheid Israeli state, which is what I think they mean by it. Israel could also refer to all the jews in Palestine, in which case destruction would mean genocide, that is probably what most Israelis think they mean by it. Depends on how cynical / what side your on as to what you belive Israel refers to.

I think that those in the occupied territories are more likely to want the latter as they've had more antisemitism bread into them by both there culture and repeated bombings by Israel and violence from settlers, but still a majority would want the former. Iran is further from the destruction caused and is more likely to view Israel how the US views Iran, run by a bad regime that once it's toppled will stop it's aggressive ways.

Not necessarily, depends on what replaces it. If it's replaced by a functional secular democracy then yeah that would be better for Iran, but thats probably the least likely scenario. Most likely it will either be replaced by:

1. A new dictatorship after a civil war, tons of Iranians die and not much improvement is made to the quality of life in the end. Maybe the new dictatorship is more secular but it could also get rid of some of the democratic elements in the current regime.
2. Iran turns into a factionalized failed state like Libya or Syria, kept in a perpetual civil war by greater powers using it as a playground to test their newest military equipment.

2 is the scenario Israel wants, as whatever regime takes power will probably be anti-israel after this latest attack so itd be better for them if that regime doesnt have any power. Its also the most likely to happen if the ayatollah regime falls during this war as the mossad has shown they have a lot of capacity in iran to engineer this result. It's also the worst scenario for the Iranian people.