1. what causes the relationships with the pope to go down (besides attacking catholic factions).
from my observation: Executing Catholic prisoners (even when the ransom is refused), Sacking a catholic settlement, attacking a catholic army (even if it's besieging your settlement). can some one back this up.

2. How to win favor with the pope? Building churches doesn't seem to do it.

3. What stops factions from being excommunicated? I've been attacked by Denmark, Poland, Venice, France, Milan, multiple times a turn for the last 20 turns, no one has been excommunicated.

4. Guilds. Is it possible to have multiple guilds in one settlement.