in my current game, i have made it my mission to only make 1 quadrant of the game my core. that corner is slowly being absorbed into my culture and teched up. for the other 75% of the map, i go on punitive expeditions that begin as occupations and end as raids. for example gaul will be part of my culture but britain will not. i occupy gallic cities and get rid of the culture penalty. britain will not be. so when i'm at war with them, i occupy all their cities[to prevent them regaining it throug civil revolt] until i have destoryed the british faction. then i destroy all the buildings in the formely british cities and move my troops towards germany. while rebels now occupy britain. then i repeat the process for germany.