1) Is this [conspiracy theories] mainly the purview of paranoids?
I don't know, but you can break both paranoids and conspiracy theorists into two similar camps.
Primary - Conspiracy theorist originators and full blown paranoids. Full blown paranoids are less likely to believe others' conspiracy theories and more likely to create their own (because they don't trust anyone, including other conspiracy theorists).
Secondary - Conspiracy theory followers and people with just paranoid traits. I think a lot of these people just don't want to appear naive. It's kind of "cool" to not believe the official line. So, there could be a lot of people in this camp who don't even have much paranoid traits at all. But, for them personally, it is much better socially to appear like they're not gullible enough to believe everything science and the government tells them.
2) Is there anyway to break out of this belief in perception?
For the primary camp, years of therapy? The prognosis for Paranoid Personality Disorder is not very positive.
For the secondary camp, maturity? It's almost like they're teenagers, rebelling against authority.
Edit - Come to think of it, conspiracy theories seem to flourish where the standard sources of information are unreliable or downright deceptive. Russia and the authoritarian regimes of the Middle East come to mind. It seems like our society is in that kind of state right now. The main source of information (the internet) is unreliable or downright deceptive. So, I dunno, get rid of the internet?