It's really a sad situation for a family that goes through a divorce, and I say family because it ends up affecting everyone. In my case, I'm the kid of divorced parents, in a utterly brutal feud that continues to this day, 29 years later.
My parents were the ones that did everything wrong. They argued like children in front of my sister and I, fought back and forth over my sister and I for years. My stepmom played my mother against my father and against me. My father hired private detectives to watch my mother and sister. One year, my dad drove over 1500 miles to snacth my sister away from my mom, in front of me and 2 other step children. When I visited my mother, she used to take me to the hospital and tried to get the doctors to say that my stepmother used to put out cigarettes on my body. It gets worse, but that's not the point. (I'm happily married 10+ years now, and I'm not letting their mess rob me of my happiness with my own family, thank the Lord!!)
What I'm trying to say is that taking the high road and being the good-hearted dad will go so much further than the jerks my parents were in front of us kids. Never let your "horns" out in front of your daughter or your ex. As someone said earlier, it takes 10 good memories to cover up one bad one, and let me tell you I still remember most of their crap to this day.
Unfortunately, in this age of lawyers, it is really only the divorce settlement that holds any water. Anything else off the record can be likely used against you if opportunity presents itself, expecially if your ex is a spiteful revengeful person. If she is, she is the one living in the prison of herself, and by walking the straight line, you will show your maturity and responsibility. I don't know your ex Ida, but I know you pretty well, and you are one of the friendliest people around, so I'm probably making a good guess as to who the problem is here. I think you are doing the right thing by thinking this through with your buddies before you react. And document, document, document......
