I don't think fundamentalism itself is at all wrong or dangerous.
Really, I don't. Not any moreso than scientology or atheism. It just so happens that those religious fundamentalists do bad things because of their religion.
But, let's take Jack Chick (since he's been such a fine topic of conversation as of late). He's obviously a fundamentalist. Is he doing anything morally wrong? He's not forcing his beliefs on anyone. He's not protesting funerals or saying that we should kill a group of people.
No, I don't think so. ZOMG he makes religious tracts. Who cares? He's not making people read them or believe them, so he's doing nothing wrong. His type of religious fundamentalism, while annoying, isn't doing anything wrong (and even the actions of the Westboro Baptist Church could be disputed as not doing anything wrong, aside from being *******-ish).
If Chick were to do something like, oh, I don't know, go on a murderous rampage in a gay bar because, as Alliance so aptly put it in another thread, "F@gs will burn," then, yes, that would be A Very Bad Thing and morally wrong.
The beliefs really aren't dangerous, much like racism. Racism itself isn't dangerous, even the most extreme of the beliefs (that one race should rule over another). It only becomes dangerous when people think they are allowed to act on these beliefs in a way that is detrimental to others.