I hear it used as justification for neighbor actions ie Saddam invading and lesser known that next door in Afghanistan the communist were very paranoid of Khomeini pushing into Herat and even thought he was behind a uprising in Herat( he was not). So how of threat really were they at this point?
I think there's a few things to note about this question. One is that unless we get into modern political issues about whether Iran is currently, over the past ten years or more, spreading "revolution," that the question is basically counterfactual and therefore difficult to answer.
But to get to the substance of your question, I think you have to bear in mind just how fundamentally world-altering 1979 was in political terms for the region. In that year, in order, you had:
These five events totally changed the regional political outlook and cold war balance. Dealing with that new political calculus had huge ramifications and led, in some cases, to some very poor decision making.
It's worth noting as well that while the Islamic Revolution in Iran was a Shia phenomenon it was taken as an example by Islamist movements regardless of sect, or otherwise seen as the ultimate example of a very real rising power of Islamism across the region. So in 1979 you also saw the seizure of the Grand Mosque in Mecca, and the burning of the US Embassy in Pakistan.
Within the next 36 months these regional convulsions continued. The launch of the Iran-Iraq War, the assassination of Anwar Sadat, the American decision to arm the Mujahideen, the election of Ronald Reagan, US intervention in Lebanon, the Beirut Embassy bombing and the birth of Hezbollah, the Israeli invasion of Lebanon and on and on.
So while there was certainly a degree of paranoia about Iran in particular it's because it was seen as a catalyst for or mark of very real and incredibly significant changes in the region.
Source wise a good overview of the time period can be found in either Eugene Rogan's The Arabs: A History or Steve Coll's Ghost Wars.