I'd let my kids play the game at an early(Lan/Singleplayer).
Playing online and joining the forums? Not even going to happen, unless this community somehow becomes "friendlier/cleaner". I wonder why parents flip out when they see whats on these forums?
Then again, i'll probably allow it if they're mature enough, but there will be some rules. For example: Staying out of Off-Topic, a limit of 2-5 add-ons per day, a limit of 2 topics a week, etc.