Thanks for all the replies and advice, it's all very appreciated.
I'll stick at it giving them all equal game time. It's such a rewarding experience and I'd love to see them all develop through the age-groups.
Most of the parents have been great and very supportive; they know I stepped up when we found ourselves without a coach and how much time and effort I devote to the team and I've only got their boys best interests at heart. The parents who don't see that have gone, I just feel sorry for their kids who I feel will suffer in the long run.