Most of the above will probably need tightening, and that is all, kids dont generally wreck the bike through riding it, but what i would pay special attention to is the bottom bracket and pedal arms. ( the bottom bracket is the part that the pedal arms revolve around, the spindle that connects the pedal arms), this is usually the area on a kids bike that gets abused because when they are playing they dont consider standing the bike against a wall or something sensible like that, they usually just drop them on the floor, and that hammers the hell out of the bottom bracket.