SE's? Srsly, that's what's holding you back? Build a siege workshop, wait a few days, then attack!
Madina produces very little gold, I think. Not thinking the rebels would secede, we forced Sage out of Madina's ducal seat (long story short, we didn't like him) by making it rebel. Now we can't build SE there until the city is repaired a little more - someone could probably just lend Abbot the gold, but Madina is a funny place like that