I fly Air NZ regularly:
- Laptop on econcomy
Air NZ's entertainment system is fantastic and provides hours of childrens programming on demand, from as soon as you are seated on the plane. There are powerpoints in premium economy seats and business first but its unlikely they can charge anything up for you - but you won't need it.
- toddler headphones
Have no idea about these but noise cancelling headphones are tremendously expensive for adults, I've never seen any suitable for toddlers.
- Bugaboo on flight
YOu don't have to have a bag for your pushchair but it helps protect it. I've travelled with a travel bag (for a Micralite) and without (for a Maclaren) and its made no difference. In the case of the Micralite it was slightly useful because the bag has a shoulderstrap but the distance you have to carry is very short - from the gate to where they ask you to leave checked buggies... which can be the same place....!
- toddler rucksack
I'd like to get a bag for her things for the flight (for her to carry!), preferably one with lots of pockets! Can you recommend any nice ones? I have looked at those pull along/ride on suitcases but think they may be a bit large.
Can't comment, neither of my children would ever wear a backpack for any useful length of time and its another thing for them to discard when you're not looking and leave behind somewhere in the terminal... For that reason I take a carryon with everything they need, because i don't want anything else to worry about losing. (And which i'll end up carrying anyway.)
- snacks/drinks on flight
Can you take food for LO's on with you? I'm thining biscuits, drinks, raisins etc...
YES - LOAD UP said bag with as much as you can carry! You can never have too many snacks! Buy drinks after security, inside the terminal though, otherwise it will be confiscated when you go through security.
- Travel sickness
Sorry have no experience of this but as someone who used to get terribly travel sick herself as a child, it was only a problem on smaller planes with prolonged turbulance. Air NZ has only 777 or 747's for long haul which are huge and they fly at such altitude turbulance never lasts very long and they fly the planes out of it so to avoid it so its never a problem and never enough to feel ill.
Take spare clothes and layers to be able to warm up cool down easily. And wear/take spare clothes yourself if you can, in case of food & drink related accidents... I ended wearing a sticky fruit smoothie for a 4 hr journey to Greece once, and that was bad enough!
Btw, the transfer at Auckland International Terminal to Auckland Domestic to get the plane to Wellington is quite annoying. You have to collect your bags and drop them off again to be transferred to the domestic terminal, or else load them onto a trolley and push them across yourself... There is a bus shuttle transfer but i tend to walk (its clearly marked, just follow the blue line painted on the pavement) because I need to stretch my legs!
I'm going down to Wellington end of April, I do this trip yearly. Which way are you going, via HK or LAX? HK is good, you're allowed out into the terminal to walk around, in LAX you may be trapped in a transit lounge which is quite... confining! YOu can recharge anything electrical in LAX or HK if you have the right adapters (just look for a socket somewhere!) and both airports have free wifi. (In HK it is public, in LAX theres wifi in the transit lounge but you need a password which the staff will hand out when asked)
Good luck!