Iran does not need nuclear power they have an abundence of oil.
With a change in gov't, there will be so many social and economic changes necessary and money will have to be spent on the people and infrastructure. (things they aren't spent on much now). The new gov't won't be spending time and money on nukes.
Iran isn't a muslim country in the sense that arabic countries are. Islam was imposed upon the Persians. Years of oppression under extremist muslim rule have taken their toll. When the mullahs are gone, there will be many changes.