I guess its kind of like the Catholicism of Islam.
Quite the contrary. Shi'a Islam is not at all bound to listening to the Tradition as much as Sunni Islam is. Therefor, Ayatollah Khomeini issued a fatwa on sexchanges, in that it is legal. The difference between the ayatollah and the mufti is that the ayatollah has way more influence when it comes to (re)interpretation of the scripture. A mufti can only give advice without interpretating a text in different ways, while a Shi'a cleric can have a totally different interpretation of those same texts. It's the same reason why the Hadiths are less vital in Shi'a Islam than in Sunni Islam. Then there's the difference between Ismai'li Shi'a and Twelver Shi'a, but that's somewhat less important for this discussion.

The modernisation of Islam WILL start in Iran I'm sure of it.
Yeah, only that the modernisation of Shi'a Islam will have influence only in Afghanistan, Iran, Iraq and bits of Azarbaijan. You're making the same mistake here many people do, and that is by thinking that a Shi'ite religious authority has as much authority on Sunni Islam as they have on Shi'a Islam. That's not true. In essence, a Sunni Muslim can reject anything a Shi'a cleric say, simply because he is Shi'a.

If you want Sunni Islam to reform, take a look at this guy's works, for example.