It seems to me that you are actually o.k. with using the word lunatic for describing dangerous and/or silly beliefs, given the list you gave. The only one in that list I would agree might be a lunatic, as in actually mentally ill, is Jim Jones, because he orchestrated what he did where everyone else is just following the beliefs they hold to be true and acted in accordance with those beliefs. Weird, yep...silly, yep....dangerous, yep....but I don't think insane.
That's taking some liberty with the interpretation of what I said. I do think that the dangerous ones out there - the jihadists, Jim Jones/David Koresh and their ilk, and Westboro among others - are lunatics. And dangerous. Tom Cruise was included as a joke but regardless that's a strange dude, scientologist or not. If we don't agree that flying planes into the WTC and killing thousands of innocent people is lunacy, I'm OK with that and comfortable with my side of the discussion. Same with Westboro - I believe they have misinterpreted and twisted things to fit an agenda and have done so with a hateful obsession that indicates mental instability.