I feel your pain, Barrister Boy.
At least once I've gone from tarnished to dishonourable scum completely by accident, precipitating a bad boy war that wouldnt have happened even if I annexed every province in the offending country. The worst is when you have CB shields on the provinces, and you get stuck with the provinces in a turbo-annex. Thats 3 BB per province when they should be free... Arg!
I agree that the penalty should be reduced to 2 BB, just like normal annexation. That makes complete sense and prevents this game feature from being exploited.
If its one thing people tend to forget is that government collapse is in the game for a reason. Its intended as a feature that prevents countries from refusing peace deals continously when there is no hope of rescue. (Hence the stability loss for refusing reasonable peace offers as well). Penalizing people excessively for making use of government collapse prevents them from using a good strategy that has historical basis: invade the enemy when they have internal problems. As it stands now, I'd refuse to get involved in someone's civil war simply to prevent a horde of extra BB that I dont need.