I think a phone time limit should be imposed. My husband's ex would call his sons morning, noon, and night when they were with us every other weekend and spend at least 10-15 minutes with each one on the phone. It was evident by their answers what she was asking. What did you have for breakfast, dinner, etc. I just wanted to check and make sure you were safe, etc. It interrupted the father/son bonding time and their moods would also change. I have seen the divorce/custody from both sides since I am also divorced with children. It is impossible for a parent to stay connected with only every other week visitation, especially if it is constantly interrupted by the other parent. Many people disagree vehemently with me but every other week is the ideal. The children are able to interact with both parents by having alone time. Rules should remain consistent between the houses and open communication is key. The children have a right to two parents and excuse the language but the parents need to just suck it up. I do know that in some cases, it would not be good for the health of the child to have that extended amount of time with a parent. There are always exceptions.
The danger in proposing laws that will allow this is that the parents who fall into your category of "not being good for the health of a child" will slip thorugh the cracks and the kids will get hurt. The parents who can cooperate are doing, the ones who cannot (either the small percentage who are mentally ill and the remainder who are affected by abuse and violence) are not cooperating. And that larger percentage of the non-cooperating parents who have been dealing with abuse and violence are the ones we are trying to help.