Throw ups should be vastly reduced by following a similar principle to rugby and just overturning a free due to foul play/dissent etc. Throw up's often flare up incidents, whereas if the play was overturned to the opposition then the game can begin straight away and leave less standing around waiting for aggro to start! Only scenarios where it is not known who the ball should be awarded too (e.g. a line ball) should there be a throw up.