Basically, no heavy case pyro to be thrown, it must be dropped from below knee height or rolled but only after checking you arent about to drop it on someones head as even from below knee height it will fucking hurt. Paper pyro only to be thrown.
Its an added cost to get specific armbands and enough of them, but one I think would add to peoples experience. You would either get very few issues as people behaved themselves more if they knew they could be readily ID'd or fucking loads, it could go either way. Maybe add £1 deposit for each armband refundable at the end of the day to ensure they dont get nicked which would be the main issue.