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 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.
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).
Yes, although it is hardly an easy task. Many countries have separated church and state. They either have seen the dismal result of their own theocratic history or else they look to such countries as Iran and Saudi Arabia today where religion is a compulsory part of society and law.A truly free society must separate the two, for religion is a personal belief and should never be a part of any government that serves all citizens.
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".
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.
The government allows several specific churches, but conversion from Islam to another religion is prohibited.
Present day Iran. Read the news!
The current (as of 2011) government in Iran is strongly influenced by religion, or rather by religious intolerance. As a result of their particular interpretation of religion, women have hardly any rights, anybody who changes his religion from Islam to some other religion risks his life (for "apostasy"), and religious minorities (especially the bahá'ís) suffer a lot of persecution.