I am currently working in US on H-1B visa (I do not have green card or US citizenship). I am moving to NZ next month and my employer is planning to hire me as a contractor.

I checked with CPA in US that only residents(green card holders and US Citizens) are required to pay taxes in US.
My questions are

1.) Since I will be working remotely for this employer from NZ, how much taxes I need to pay in New Zealand.
2.) To pay taxes in NZ, I need to apply for an IRD number, is that correct?
3.) Are there any other requirements from New Zealand tax purposes?