I certainly don't see any kind of skeptical fans as fanatical. In fact they should, by all rights be "fanaticism proof", (normal human tendencies notwithstanding). Steve is my favourite skeptic, but if he said something that didn't match with reality, I'd have no qualms about questioning it.
Yeah I agree, the term "fan" might carry extremist overtones, but I think there are different levels of "fandom". From mild respect to full-on stalkers to cult-followers.
I'm a fan of the skeptics' guide, a fan of each panelist, hell I'm a fan of most of you on here. But like you said, say, Jay decided to turn to Tom Cruise and Scientology one day and tried to convert us, I would not follow. If Steve became a Homeopath, I would not accept homeopathy. If Perry said he found bigfoot, I would question it and demand proof. If Bob decided to declare the face on Mars an alien structure, I would laugh and point. If Evan ever says "god did it", I would bow my head in shame. And if Rebecca ever turned to vegetarianism..... oh.. wait. Bah, I still eat steak!