Starting in London (any airport) in mid April, dates are flexible both ends, and returning mid July, flying to/from Auckland.

I would like to do a 24h+ stopover in an Asian city on both outbound and inbound, to see a bit more of the world and also help ease jetlag. My research so far has suggested Hong Kong or Shanghai for the stopover as they are good to get a feel of in 24hours and I have never been. Any advice on either of these? Is there likely to be a cheap hotel/hostel option in either of these?

Once I get to NZ I have found a travel pass that allows for flexible time spent in each place (http://www.epicgapyear.com/portfolio_page/kiwi-experience-travel-passes-new-zealand/) Possibly the "funky chicken" option on the whole country passes. Does this miss out any places you feel I should DEFINITELY go to? Have heard this is a party bus, not what Im looking for, so looking at this kind of thing instead http://nakedbus.com/nz/passport/suggested-itinerary-unlimited-trip-pass/.
I may be returning for a year with a working visa at a later date, so I should have the chance to see anything I miss. Does this seem like a good value for money way to get around? Would I be missing anything by not hiring a car for example? Has anyone here tried this and has any comments? Also would this route take me near enough to "Hobbitton" to visit? This is definitely near the top of my list!

Im really interested in the great outdoors, I love mountains and lakes and the kinds of terrain NZ seems to have, though my fitness level is not at hiking a whole mountain. I would love to go for some day hikes that arent massively strenuous. Ive been to Canada (Bowron Lakes, near Quesnel, BC) and done a 10 day canoeing trip (not solo, with a canoeing buddy), France, USA, Spain, Italy, Switzerland, Belgium, Netherlands, Germany, Australia (when I was a kid with family). Id prefer to stay in hostels/couch surf (not sure how safe the latter is for a solo female traveller..?) and keep accommodation as cheap as possible, I am more than happy to camp etc if its suitable (not sure about the climate this time of year) Ive read a bit about budgeting (eg http://www.nomadicmatt.com/travel-blogs/budgeting-in-new-zealand/) and have set a provisional budget of £1000 per month (NZ$2000), plus flights, which works out to around NZ$66 per day. Is this reasonable? Id like to be able to eat out occasionally, but Im prepared to cook most meals myself, and Im not a big drinker.

Hope this isnt TMI in one go, Ill try to clarify if you have any questions. Response to any of the million questions would be great! EDIT: dont like party buses