No, I just spent a week there; and had to clear customs from the International terminal at both Auckland and Alofi. As a New Zealand passport holder I am treated like any other foreigner - an entry stamp on arrival allowing a 30-day entry only, employment prohibited. Also see here.
So Switzerland and Vatican City weren't countries when they were not a part of the UN? And I suppose before the UN was founded in 1946 the world had no countries at all?
It's really not except for defense. It's basically what Marshall Islands is to the United States, except for some reason QM doesn't recognize Niue and Cook Islands as the independent nations they are.