S.G.
I think the major issue here is who has custody. If you have custody then you make the rules and your ex should abide by them. If however he has joint custody then he has the rights to make certain decisions when your child is with him. As far as who picks him up from school that is between the school and the person who has custody. So if you husband again has custody or shares it with you he can specify a certain person to pick him up.
If on the other hand you ex has no custody and only visitation, then you have certain rights.
My only question to you would be why you care so much about the child care issue. His father has certain people in his life, and those people are a part of your childs life as well. If he had to work or chose to work it may be because he had so many bills that needed to paid and working was somehting he really needed to do. Should he give up his time with his son because he had obligations to meet financially as well. If he provided for him by having someone watch him, and they took care of him, why should it bother you so much?
Soemtimes mothers believe that the only people their children should be with during visitation is the father. Life is not perfect and when families are seperated we deal with the imperfections. If he was cared for, if he had a good time when dad was not working, why would you make a big deal out of it. If he had not worked and could not make his child support payments would you be upset with then as well?
Give him a break for trying to do the best he can, at least he did leave not him with strangers.