Flying pigs!
Now there's a name for an expansion I could get behind
Your cloister idea sounds interesting, I just wish there was some way to place the pig and get it back, a la the builder. Maybe having the majority in a city with a pig on an adjacent farm gave you 10 bonus points and returned the pig to your store, something like that. As it is now it's just placed at the end of the game, half the time not really where you want it, and the other half people just forget about it.
Getting 5-15 more points in a 200 point game isn't usually the most vital move to make, especially since it's often a gamble where it'll be most needed until you're fairly close to the end.