Colonial nations are way to easy to manage atm.
Only if you don't count the idiotic micro hell of helping them with their rebels.
CNs are the most micro-intensive feature in the game. You have no way of automating rebel suppression there and the AI is so bad at it that it will get provinces occupied at sub-100% OE even when it has enough units to win. As a bonus, CNs will also freeze up in terms of converting religions (even in situations where a tag switch clearly shows they can easily convert every province in 30 months or less) and if rebels occupy a province they've not yet cored, they won't core it even though they have the ADM to do so in some cases.
I get that you mean wrt them rebelling, but CNs are anything BUT easy to manage from a micro standpoint. They're the worst micro hell in the game. At least you can auto-hunt your own rebels, even if the game sucks at it and will let a stack march across Asia "hunting" a stack that was killed months ago.......................
By the way, I'm not amused that USA gets cores on Aztec, Iroquois, and other NA natives in their original culture. Shouldn't there be a flag preventing that if the culture isn't European?