Pippin You're right, don't do anything until something needs to be done. I'm going down the happines is the best revenge route too, even become a student again, although not in a position to have my own home yet, but i will once i get my qualification and a better paid job.
My ex filed for divorce 9 months after moving out, he threatened me for months in emails before that he had the most dreadful reasons to use for unreasonable behaviour about me. I was worried sick at the time what he could possibly put, but when i finally received the divorce petition, i laughed, he'd put the opposite of what had happened when he was still living with me, even putting the opposite of what was in emails between us (we used to email each other several times a day when we were at work). Am 100% positive he thought i'd defend being divorced on such grounds, but i had a free 30 mins with a solicitor, was all i could afford, and she told me it would cost so much to defend, i'd still be divorced so i might as well let him do it on lies. A year later, i think the rush was because he was worried i'd file on his adultery and he was worried about his Mums reaction, and as he told me about the OW in yet another email i had my proof to use, his Mum has told me it was my fault we got divorced, the papers say so!! Even though hes living with the OW, and i'm single its still my fault. I'm also so glad i didn't somehow get the money to pay for the divorce, once he'd gone off with someone else, i really didn't care about the paper bit of being married. Last week i was looking for something and found our wedding rings, within a day i'd sold them at a jewellers, will be using the money next Saturday to go out with my 2 younger sons for the day, will be climbing a large hill in the Peak District and having a toast, with a soft drink, at the top. My way of celebrating the end of my marriage, to a man who was fantastic for over 25 years, but then suddenly changed into a monster i didn't know, we're in the family courts again the week after.
So pippin having a happy nice life is the answer, leave your ex to his own arguments. Sure in a year or so you'll look back on this time and be glad you did. :)