Budwise:

Sounds like you are having a great game. There are always ways to make for a challenging game.

BTW, if you want an even tougher game:

After you have selected the faction you want to play, give ALL other factions 500,000 to 1,000,000 florins.

This way only you have to worry about building up an income; the AI doesn't have to worry about it. Imagine playing against that UBER Pope who will never go bankrupt...

I have been spanked badly by the AI in several games...

Cheers!