Isn't there also a somewhat unofficial rule where to get on the ballot you have to be approved by Ayatollah Khamenei?
It's not even unofficial. To become a candidate for the Iranian presidency, you need to be approved by the Guardian Council, a twelve member body where six members are appointed by the Supreme Leader (presently Khamenei) and six are appointed by Parliament. The six members appointed by the Supreme Leader can be dismissed at will, and are entirely dependent on his approval to retain their position - making them just de facto representatives of the Supreme Leader and in doing so giving the Supreme Leader a veto on all candidates.
The kicker is that while Parliament can vote to approve the other six, they have to be nominated by the head of the Iranian judiciary... who is himself appointed by the Supreme Leader. So six are controlled by the Supreme Leader outright, and six are a compromise between Parliament and the Supreme Leader, except access to Parliament is controlled by the Guardian Council with all candidates requiring vetting, which as you can see is dominated by the Supreme Leader...
Basically, yeah. Very, very slowly, over time, Iran is becoming more liberal, in that a few reformist candidates slip through the gaps for Parliament, the six members of the Supreme Council that need Parliamentary approval as well become ever so slightly more moderated as a result, and then a few more reformist candidates slip through the gaps as a result. But it's a process of fighting for inches, not miles.
