None of your options would pass for scrutineering at an ALRC event, there are not supposed to be 'welded'..... i have seen a reciever type hich get past a scrutineer, but he insisted that the pin be swapped for an 8.8 rated bolt, so if you have concerns, do that, and maybe use a nyloc nut, it will mean taking a pair of spanners to it to fit/remove it, but thats small price to pay, plus it actually makes it less liekly for someone to nick the hitch, or even whatever trailer you might be towing!!
People don;t seem to consider the option that theieves might actually unbolt a ball hitch to nick a trailer, everyone locks to trailer to the ball, and then has two bolts holding it on, anyone serious would just undo the bolts!