B772 could do Kalgoorlie, B773 doubtful due to the fuselage length. Remember if you're diverting it's very likely other aircraft are as well which creates ground handling problems at the alternates.
CAT 2 Landing capability is routine worldwide and is even found in some third world countries. It's very disappointing that a capital city airport which is isolated and fog prone can't provide it when most of the major airline jets flying there are CAT 3 auto land equipped.