-- the important difference between the two being that, whereas the logic of anarchism is completely irrefutable, there is usually some important defect in the average conspiracy theory.
But although I see the dichotomous contrast between anarchism and opportunism (minoritarian correctitude versus majoritarian ignorance, stupidity, evil, bad taste and general squareness) I don't see one between opportunism and conspiracy theorizing. Lots of conspiratism is opportunistically promoted in the mainstream. In the mainstream media, "conspiracy", the word, is a propaganda tool, like "cult", "sect", "terrorism", and so on. If someone complains about the FBI going through library records, for instance, it's a "conspiracy" until it's shown to be true, after which the mainstreamers shrug and go on to promoting other lies.
-- Gordon