If a parent can't be in the pressbox for 1 minute out of sight to gun his kid their is a problem. That Coach sounds like a control freak. In our class we have won more playoff games this decade than anybody. We had a Coach who wanted no help and kept the parents away he won 22% of his games. We provide money and he Coaches never had a problem.
Conversely, I would cut your son's *** that day. Your parent-run club sounds like a coach's nightmare. The day parents are able to have that kind of power is the day a coach loses any kind of autonomy to make the right decisions. You probably don't understand that.
So if the parents do something wrong you run the kid off. That is a sick way of doing things sounds like you do not have enought backbone or guts to stand up to parents and just cut kids to stop the parents you are scared of.