The name is Porter ;
Collins descended below MSA based on achieving visual reference with ground or water .................................................
NO, Collins was in VMC when he descended as per the Air NZ SOPs.
Collins subsequently lost visual reference .............................................
.another assumption with no evidence to support it.
Assuming that all of the above is correct, had Collins made a missed approach based on the route he thought he was on, would the aircraft have been safe?
A ambiguous question and based on your own incorrect assumptions, answering it would require too much speculation. What
is indisputable and a fact, the final waypoint was changed the night before the flight by the Air New Zealand navigation department and they failed to advise Jim Collins and his crew.