I travelled in Iran a bit. I'd say it's pretty safe as long as you don't protest the government or contradict their religious views. My mum is a Bahai and deals with quite a lot of Iranian Bahais who get imprisoned, killed etc for believing in the wrong version of god. Bahaism is kind of an offshoot of islam and are generally more tolerant and less violent so they get killed as heretics by the lovely islamists.