This might be grasping at straws (probably) but... ...That other kid in Iowa with kid Kirk. The one he passed on the road after stealing the car. The one that, really, should have been his older brother Sam but yet wasn't, because Sam doesn't seem to exist in the JJ-verse... ...kid Kirk called out to him. His name was Johnny. Maybe... Johnny Harrison? Could BC's big secret villain be Kirk's childhood friend/step-brother?/whatever??