That is not the case in SAudi Arabia (which has no non-Moslems, it is illegal), nor in Pakistan.
As you know my mother is Iranian-Zoroastrian by birth and I still have (Zoroastrian) relatives in Iran, therefore, also have inside knowledge.
Conversion to another religion for a muslim by birth, if found out by the regime, is not tolerated at all. The current constitution of Iran clearly favors a very specific sect of Islam; that being the Jafari Shia 12ers sect. Even Sunni-Iranians are discriminated against. In that sense, the mullahs regime is not any better than SA or Pakistan.
Furthermore, although all 'officially recognized' religious minorities (Zoroastrians, Jews and Christians) have token representation in IRI's parliament, and in fact it is guaranteed in the current constitution, politically they've extremely limited influence.
They are free to worship indoors in their places of worship. But not permitted to proselytize. There is some discrimination in public housing, employment and education too. Preference is given to Shia musims. However, in recent years, Zoroastrians, for example, are quite free to hold their various religious festivals outdoors. Surprisingly or not, these festivals attract many muslim born Iranians, and the authorities mostly let it be.
It's worthwhile to mention that the Islamic regime in Iran, equally, has issues with traditional non-Islamic Iranian national festivals such as No-Rooz (Iranian New Year), which is really based on Zoroastrian traditions. It views it as un-Islamic, and several times over the past 35 years has tried to ban it, but Iranians have seriously resisted that attempt. So, the regime has tried to 'Islamize' the celebrations.
On a related note, Iran still has many regular Parsees (Zoroastrian community in India) visiting the country as part of their 'pilgrimage' to Chak Chak in Yazd province and also Kerman province, or just generally as tourists. They're very free to do so, and in fact that key Zoroastrian shrine is protected by the regime.
There is more say, but hope the above gives you some idea. :)
Yes. But lets take TJ is in context. Iran is not the same level of evil as Saudi Arabia or Pakistan