Secondly, you want a man to trust you wholeheartedly and trust in God that a divorce would never happen. Yet in the example you give, a divorce is gotten and she moves out after SHE CHEATED, and that's ok. How is that fair? I don't think the Church would allow her to divorce due to a need for $, so if she did go along with it, she is doing an immoral act.
Let's pretend that a woman didn't do anything wrong and she just needs to separate from the man due to his pornography. Ok, but is she allowed to divorce now, because she *needs* (her emotions) to separate from him? And what if he said he's not giving her $ because he feels the separation is rash, because she won't talk about their problems or go to a counselor? Is she allowed to get a divorce? No.
Lost in all this is the woman's obligation to trust God (just like she expects her husband to trust her and not force a prenup) if marriage gets rough. The marriage vows say for better OR WORSE. Well, when things get worse, you can't go running to the courts to get some "financial security". That's not catholic thinking and is immoral. If you have a legitimate reason to separate for a time, then you must trust in God to provide for you during that brief period, because catholic thinking is that a separation is to HELP THE MARRIAGE HEAL, to lay down consequences, to "wake up" the spouse that is lethargic in their duties. If you go and get a divorce, you are furthering the stress that is already threatening to break your marriage. A separation is meant for prayer, reflection (for both parties, because problems are usually never one-sided) and a change in mindset. It is not a time to give up and get a divorce. Getting a divorce in this situation would NOT be a means to compromise and peace - it would be like throwing gas on a fire.