Relgious fanaticism has been around since man learned to find enough food easily to have time to think. And since man had time enough to think he started controlling and / or dominating the thoughts of others in more and more efficient ways...
Gaming takes the other way, the path of distraction.
If it distracts you to play a fanatic and you use the RP to learn something about fanaticism, or at least THINK about that topic it could be a good thing. But the problem is that this is no fun topic, and there is nothing to attract more FLAMEZ than belief.
There is a Server rule about harrassing and trolling, is there not ?
I do not think it a wise move to play a harrassing and trolling character and then try and argue that it´s all in RP, it takes too much time from the Admins and probably does not really bring good RP or more activity to the server.
It might bring some nice FLAMEZ though.
Pass me the popcorn please.
Edit : on second thought :
Why can´t you take the accepted and already well established role and play a cool blooded powermonger who only pretends to be a religious fanatic ? You would not even have to found any secret Order for that...