You have to take the appropriate part of the practical test if you have held your UK licence for less than two years. (Page 3 of this form.
http://www.nzta.govt.nz/resources/ap...5/docs/dl5.pdf)
I don't understand why you're asking. If it's, can you 'use' those six months later on, no, you can't.
Yes. And the 12 months starts again ANY time you enter NZ - so if you were to have a shopping trip to Australia, say, just before your first 12 months was up, you'd have another legal 12 months on NZ roads.
Emphatically, yes, they DO. And people have been known to get demerit points for infringements of traffic laws stacked up ready for the NZ licence they haven't even got yet, for driving while unlicensed. Too many demerit points withing a two-year period can get the licence suspended.
http://www.nzta.govt.nz/resources/fa...-offences.html
If you've held your UK licence for two years or more, you fill in the form and either do the eye test at the office, or show an optician's certificate to show you meet the standard. See here.
http://www.nzta.govt.nz/licence/resi...riving-nz.html If you've not held it that long, you'd first get a NZ restricted licence, with the conditions of use mentioned here.
http://www.nzta.govt.nz/licence/gett...r-licence.html
In that case, can you envisage a quick trip out of NZ in, say, September, 2015? You would then have the right to be on your UK driving licence till September, 2016, and when you came to convert it, you would have held it for more than two years.
Details here.
http://www.nzta.govt.nz/resources/ro...ving-test.html