Diplomatic reputation and popey

So what is the deal with your diplomatic reputation when you engage in diplomacy.

Ive never broken a treaty or declared war on anyone yet my reputation is apparently 'untrustworthy'....?

:help:

Is this reputation effected by anything else? Such as how much you use assasins etc etc?

Or is this a feature that doesnt have much bearing on the realities of the game?

Oh and on the matter of the Pope, I got excommed, then I fight the pope in a land battle and kill him. Next turn an election is held and other factions are reconciled but not me...What gives???

How aggressively you take enemy cities has some bearing on your reputation as does if you eliminate other factions (taking their last city). The eliminate faction has more bearing than taking of cities. You must have eliminated multiple factions.

If you are a Catholic faction, you should build your max of priests ,preferably from a town that has a Theological Guild. Then send them to areas with low religion such as the Levant or Eastern Europe. This will give you more priest who will become cardinals allowing you to stack the College of Cardinals. Sooner or later, you will get a Pope who is from your faction. This will not free you up from "Christian responsibilities" , so you could still get excommed.