Yes. Between Islamic and Christian, between different Islamic factions (Shiite, Sunni, etc.), between fundamentalists and not-so-much-so. Members of the Baha'i Faith, the largest religious minority in Iran, are the most persecuted.
Yes. If anyone goes up against the government over there, they are separated by the religion.
The Vatican, by its nature and purpose, has no separation of state and religion. In Iran there is minimal separation of state and religion, with the secular government allowed operational freedom within narrow limits, but always subject to control and veto by the religious authorities.
There is no king of Iran. There is the spiritual leader, called the Ayatollah. Since Iran is a theocracy they follow a religion, as their government. The current Ayatollah of Iran is Ali Khamenei.
The majority religion in Iran is Shi'ite Islam.
Unlike Iran, a single individual has most of the power in Saudi Arabia.
The term that best describes a government based on religion is called a Theocracy (Theo meaning God).
Iran has a government similar to the democratic republic of the United States. The government in Turkey is based on separation of powers. Indian government is a secular democratic republic and Saudi Arabia is a monarchy.
Yes for example in Iran you must follow Muslim religious rules even if you are another religion.
That is currently happening. Several governments limit the freedom of religion. As an example, in Iran, if you change your religion (from Muslim to something else) you can get executed for "apostasy".
The government allows several specific churches, but conversion from Islam to another religion is prohibited.
Present day Iran. Read the news!
Unlike Iran, a single individual has most of the power in Saudi Arabia.
It gave Iran its language and religion.