Thanks for the email, I certainly hope you are fit as your litle adventure covers a lot of territory - all very different and at a time of the year when, weather wise, anything can happen,
Auckland for three days is a little tricky. This is an administration city and not really very geared to tourism. You could go out to One Tree Hill as a day tour but don't go too far as the ship calls at other places quite close to Auckland. If you want any woollen clothing for your next winter this would be the place to get them.
Tauranga. Really a fishing town that has discovered that its proximity to Rotorua makes it a (sort of) cruise port. Set in the Bay of Plenty it's main claim to fame apart from fishing is that it grows Kiwi Fruit for export around the world. However, the real reason for the call is to let you get to Rotorua. New Zealand is really a termal time bomb and at Rotorua you get to see and smell, the geysers of bubbling mud and stuff. If you like the smell of rotten eggs you will love this place. Still you do get to see some of the Moari culture.
Bay of Islands. Depending on where you anchor you will either land at Opua or down at, cant think of the name, could be Waitangi. Visibly very attractive but you will see better in the Whitsundays. Lots of short tours to had and you can get to see the Treaty House where the Moari wars ended.
Christchurch - Wellington - Dunedin. I have to lump these together as I have only visited a couple of times and then stayed close to the ship. These are very small cities which do have boutique tours to local places of interest but I must confess I never took any of them.
Fjordland Park. I assume they mean to steam between Stewart Isand and the South Island. Very spectacular scenery although in February the snow will be absent. You may steam into Milford Sound for a bit of a look around which is very worthwhile and a photographers dream.
Hobart. Another small city, this one sits at the base of Mt Wellington. Can be interesting if you go out to Richmond which is quite historic for Australia and (I think) boasts Australia's oldest jail. If that is not your style you can always go and lose you money at Wrest Point Casino. Some very good small restaurants are scattered around the town. Tasmania was where the bad convicts were sent and has rather a brutal history.
Melbourne:After getting through the horror that is Port Melbourne you will find a city that likes to think of itself as the "Arts Culture' Australian city. Heaps of restarants and shops to to keep you amused but not really a 'fun city' (in my opinion). If you don't want to hang around town you could take a tour out to the Dandenong Ranges, which is OK and will fill in the day.
Sydney. Only one night???. Well forget all the tours and stuff. Have a quick look at the Opera House, then pay a visit to Darling Harbour which is good to get the atmosphere of the place. Then hit the bars around the 'Rocks' area behind Circular Quay. Steeped in the history of this quite dazzling city and populated by people who are a little different to the norm. DO NOT SHOP in the Rocks as it is very expensive. You really could spend a day in the Rocks just watching the world pass by your door.
Cairns in February: Probably will be very hot and sticky, with a definate change of short sharp tropical downpours. Dunk Island is just one of the many that are scattered around the Whitsundays. You will have ball. Very 'lay back and let it happen'. Plenty of beaches, ocean and water sports, then good dining and relaxed bars in the evening. You can get some quite spectacular sunsets so be prepared.
Never been to Silky Oaks but the Daintree is certainly not to be missed. Fascinating rainforest with heaps of flora and fauna and not all the little creatures are trying to bite or sting you - only some of them.
Depending on where on the Barrier Reef you are going, there are many different things to see and do but it is mainly centred around SCUBA diving and snorkelling. The water is always warm and clear so no roblems there unless you get a tropical downpour. Just make sure that the platform you are visiting has good facilities - most of them do. Plus, I have noticed that a few people get quite affected by the motion on the big cats going out to the reef so perhaps some tablets would not be amiss.
Anyhow - I just know you are going to love it. As to the rules - well No1, just take things slow and let it happen, that is the Australian way. No2 - don't shop in the tourist areas - No3 - same as No1