I can arrange a tour if people want that but in many ways it is nicer to break off into small groups and do your own thing. There is no problem getting around. Everything is in English you can catch even local buses to the North shore and see all the local areas. The hotel will have tours on offer too that hit the highlights.
You can walk to the ferrys.
I never see my family so I will probably be visiting them during the days. My brother and sister will come to the Orbit Restaurant and be on board prior to our departure for dinner.
There is time. I can contact my tour operator for New Zealand that are centered in Auckland or you can find a company on the web. Each company will offer the same sites and excursions. The people are really nice and friendly so I bet you have a good driver whoever you use.
Auckland has a lot of traffic so although Ken and I will drive and have a vehicle I am not sure how wise this is with them driving on the wrong side of the road and many one way streets. We have been going down almost every year for about 20 years so we know Auckland well and we are comfortable driving.
Remember everyone, New Zealand is expensive!