Hi SEL,
I'm a nearly 3-year expat so will try to answer some of your questions.
My experience with job hunting is that employers are willing to be flexible, a function of the work you do likely to be more generalist, broader than what you're used to. I had specialist skills which I don't really use in my current role, but could kind of apply those skills in a different way (if that makes sense!).
I love the kiwi schools, and I wouldn't leap into Montessori before gauging the primary up the road, it may be more in line with your educational wishes than you expect. The curriculum seems far less structured than the UK, with teachers having more freedom to take classes in the direction they choose, and without the pressure of testing I saw on the UK. There is more flexibility in looking at children's needs, so that pupils repeat a year, to join at a different level, with no problems. You are guaranteed a place in your 'zoned' school, so important to pick your house carefully.
We've travelled lots in NZ, and Australia too. I thought we'd travel further, but it's actually really expensive, and a really long way from even SE Asia. In the summer holidays we don't go far, most kiwis stay in NZ for those holidays, and the whole country shuts down for a couple of weeks after Christmas.
Which probably leads in to what I miss: proximity to continental Europe, cheap travel, quality TV, radio, newspapers, Waitrose, M&S food hall and clothes shops.
The thing I found the biggest shock was how expensive day to day life can be. 3 years in I still wince at my supermarket bill, the cost of utilities, the net, electricity is shocking. Very averagely designed and made clothes are 2-3x the price of in the UK. But on the other hand certain important costs are cheaper, housing, childcare, commuting.
The wind in Welly can be brutal. But I don't think it gets really cold. And unlike in the UK you don't get those weeks of grey cloud, like someone up thread said, it will rain, the wind will blow the weather through, and even in winter you will have blue-skied sunny days where you go for a wander on the Petone foreshore, build a fort from driftwood, then warm up with the best coffee in the world at one of the many cafes on Jackson Street ????
I love it, feel very privileged to be here, it's the most wonderful place to live and bring up children, and plan to be here forever.