""So my tweek to this area is to greatly reduce loyalty in the province while a siege is ongoing to increase the chances and size of revolts and therefore make ending sieges a worthwhile task."

#1 Increasing length and support costs will fix things. Bringing on massive rebellions is just stupid and unrealistic. Your motivation for ending a siege shouldnt be derived from a fear of rebels, especially if you have 1000+ troops. And even if this was the case, with rebellions consisting of large numbers of low tech troops in the patch, a besiegers crack army could sit there and make LOTS of money and valour/rank by slaughtering rebels every turn. It would be a cheesy way to build that rank 6 general AND get cash AND take provinces all in one. I'm sorry I just think it is a very bad idea.

""So I think the loyalty again needs to be adjusted way down in conquered provinces and make it take much longer for a province to adjust to new rulers.""

#2 Utterly gutting loyalty would indeed be a good way to stop conquests, but loyalty is already a problem on expert, and making it significantly worse would slow expansion to a _very_ slow crawl, AND the money from the province wouldnt pay the support of the troops required to hold it! At that point, wtf is a player supposed to do except to spend massive amount of time teching up a few provinces, then moving on and teching up a few more, etc. It just sounds very boring. If you made every province as hard to control as Portugal, the game wouldnt be even possible for any but the best players and it would be very very slow even if you could manage to thrive.

You could mod this by changing the stats on the individual nations to reflect portugal's level of unrest.

Oh and as far as I know once trade gets started up the human can blow past economic constraints on expansion.