LNL - I think starting with a list of boundaries is a good idea. I'm not sure a letter to H is, though. It seems that setting him on the defensive doesn't work very well.
One approach might be to simply wait until the next time the money issue comes up, then simply write to him what your attorney has said. (I say wait until he brings it up again, because I have a feeling some of his bringing it up now is a reaction to him sensing you moving on. He may not be as serious about it as he seems.)
Another approach might be to simply state your current feelings - something along the lines of "Dear H, I want to remain cordial for the sake of our daughter, but I really have no feelings of any sort for you anymore, and don't desire a friendship with you. "
As for issues like meeting him for lunch, etc. - it's not his business to know why you are busy. Just tell him you are.
I just don't get the feeling that anything more than this will get you closer to your goal of minimal contact.
