Right now I only have one suggestion off the top of my head.
Buying regions is not a terrible mechanic, it is actually kinda cool. But the way it is implemented does create a leaving-a-bad-taste-in-the-mouth situation where you can just steal a region from under opponent's nose if after days and days of TO you manage to log in earlier than their ruler. This grants an unfair advantage in my opinion.
So just make buying a region a non-instant action. Make it take at least a turn and fail if the region gets a lord successfully appointed in the meantime.
