Thanks for the replies guys;

1: HRE declared war on my a few years back & attacked one of my provinces. I gave him a beating on my own turf and next turn my relationship with the pope nosedived. He was more popular with the pope than I so I reckon that was it.

2: I'm currently trying to fight off 4 factions and am in the farcical position of having to allow the danes' ships to land armies in Britain 'cos to intercept them gets me excommed!!!

3: I did use assassins extensively early in the game but now I just concentrate on killing ai assassins. I thought a successful assassination was undetected by ai faction anyhow. I only use thieves to protect my cities & to act as mobile watchtowers. I usually ransom prisoners and sack cities, as this is was the way things were done historically.

4: Yep, this has definately happened at least twice. 7-4 and 5-4 wins for my guys resulted in a hostile 4 vote cardinal becoming pope.

5: Are there any good mods out there? I've seen as much of vanilla as I can stomach. I like a long game, EB is my fave mod (roll on EB2) for Rome.