and as I was already in NZ assume it would have been activated that day
Yes.
the first 6 months were on my temp visa and wouldn't count
Yes.
Obviously, the rest of it is your business to decide upon. I didn't want to think you might have wasted the money you spent getting Residence in the first place without realizing.
BTW, 'don't want him being moved from school to school' - this can happen for all sorts of reasons even when moving
country is not in the parents' plans at all. (I went to five different schools in my time, due to one house move, a school closure, a change in the transport system, then getting to secondary age.) And anyway, not wishing you problems, but how do you KNOW that the first school he goes to will suit him better than any other? - with all the best efforts in the world, nobody CAN know that till they and the child are into the experience. Whenever there has to be a move, decent teachers are very used to easing the way when they get a newcomer, and if the parents don't talk about it as if it were the end of the world, the child will accept moves as just a normal part of life.