Do you miss something on BrainKing.com and would you like to see it here? Post your request into this board! If there is a more specific board for the request, (i.e. game rule changes etc) then it should be posted and discussed on that specific board.
I want to know why you want a teen board when this was all sparked off by a few posts by a couple of pre-teens.
I'm all for a children's board, correctly monitored, but I think you'll find that teens (at least the ones I know on here) are quite happy posting on normal boards.
As grenv said, people can be over-protective and brainking is one of the best sites for moderating.
Undesirables can be banished at the click of a mouse.