I would encourage Master Quick to join -- I'm sure he can play competively.
My own son, who is now 31 was playing computer, board and miniatures civil war games around your son's age. Fortunately there was another boy in the neighborhood and he had a ready partner, even for head-to-head PC games -- I think they started off with the SSI titles. They were attending historical miniature conventions by that time and playing against the older "boys" without any issues. Actually they were playing much better, in part because they concentrated on one set of rules - Johnny Reb - and they knew what worked and what didn't.
If there is enough interest by younger players, I think they and club would benefit if two junior "armies" were set up, with leaders who were willing to do some continuous coaching and education as well as the usual monthly tracking and reporting. That would also provide some opportunites for focused engagements among those of similar age.
Notso -- you might also want to check out the Historical Miniatures Gaming Society that sponsors some youth educational oriented competitions for prizes -- I noticed one is with the University of Maryland --
http://www.hmgs.org/charities.htm
Lt Gen Bob Breen
Commanding XIX Corps, AoS
"Defenders of the Right"