In response to your random map generator, the best I can think of is start in 1399 as a country, use the console command to annex every single country instantly and give the country ~2000 infamy and bankrupt them. They will crumble and nations will drop out of them in all kinds of interesting places.
Run the game for 20 years then pick a country of your liking.
Run the game for 20 years then pick a country of your liking.