I took both Religious Texts and Itinerant Preachers as Byzantium and the pressure form my religion was so strong it neutralized a neighbors holy city and flipped all of his nearby cities. Itinerant Preachers seems to be the stronger of the two, especially in a wide empire. The Inquisitor is really the best answer for this. I try to keep a couple around. I chased an Ethiopian GP all the way back to it's capital with two Inquisitors and a Lancer. There should be a way to tell the AI not to try converting your cities though. Holy wars should be justifiable conflicts that don't cause universal warmonger hits. I would totally understand if a neighbor went hostile after you told them to stop spreading their religion. The war(s) that follow should only affect diplomacy between the two parties involved, civilizations that share the same religions, and to a lesser extent "friends" of the involved parties. Warmonger penalties are still way too pervasive, persistent and punitive (God forbid you declare war on a civ more than once!).