Here's my .02:

H and I agreed in div that any extra expenses for s8 (mainly medical treatments) would have to be agreed on by both parties before splitting the bill, if either one of us seeks treatment for s on our own, we're stuck w/full bill.

Maybe you could make that suggestion to her, that you are not comfortable paying for a share of the activities which you had no choice in. Somehow maybe you can get the message across that you enjoy your s having these activities, but want to be involved in the decision making before you help on the money part.

As for the quit claim, I don't have any ideas on that. I'm supposed to have signed one months ago and my ex still hasn't asked me or given me any papers.

And now.... on w/sex talks!
T