1 - BA not listed on the calculator.
https://www.airnzpoints.co.nz/
2 - No lounge access in PVG from Status as don't hold status on the operating carrier
3 - AirNZ upgrade instruments are single sector
4 - It shouldn't. Who knows what will be loaded and if they will get you Y meal for you or not.
5 - It shouldn't. But generally will need to split the PNRs to apply different upgrade instruments.
6 - Polaris is no guests. For Elite Partner in IAH what does the partnet lounge page say?
https://www.airnewzealand.co.nz/part...unge-directory