Yes, this is correct, so spend you cash before you start your revolution. But in regard to the black mark, it appears from my game that over a period of time a deal broken during the anarchy period "gets around" and queers your ability to get a gpt deal.
Seems that if you have more turns left on the deal that you spend in anarchy your will not get a black mark because you are about to resume your payments after you switch governments.
Also, civs that are at war or not actively trading appear not to share the knowledge of your transgression with each other. So, you will have a bit of a grace period to make gpt deals before you rep is spread to all civs.
At least this is my observations and conclusions from my game.
I must now get back to the game, the Mongols have 5 times my culture and 35,000 or so gold. Nice neighbors I got there.