Thank you all for valuable inputs.

Decide to short it to 11-12 day, either in March (next month!) or this November,
just do most wanted (London, Dubai ,Auckland/or Queenstown, Tokyo) with miles saver bookings,

day1/2, US (evening flight) to London ,plan to arrive in the morning ,use united miles , why ,see below.
Take 8 pm Etihad flight all the way to Sydney with stop over at Abu Dubai.

So will have 10 -11 hrs in London, seems I can do a short day trip to central London. Wondering How far I can go and what/how many I can see?

Like to use AA miles, so enjoy that "apartment", it would just cost 80K for over 20 hrs of 1st class flight. Once available day was confirmed, will start book other flights
day 3: at Abu Dubai, have 14 hrs, can I see both AUH and DXB ,seems big bus only
do one side a day.
Day4, Arrive in Sydney around 7 pm, , seems Etihad can not carry me all the way to Auckland, stay Sydney for the night, is night at bondi beach a nice place to go?
day 5, catch morning flight to Auckland, just buy it as Duke787 mentioned, arrive 2-3 pm, not sure what can I do , or fly to Queenstown
day 6, pending day 4, or just a day trip from Auckland
Day7, another day in Auckland for day trip or Queenstown
Day 8, fly to Tokyo Use united miles) with free stop over night in Bangkok, arrive 9 pm
Day9, tour around central Bangkok in the morning, catch fly to Tokyo around 3 pm.
Arrive Tokyo 11 pm
Day 10, tour around Tokyo's most popular places

Day 11 ,Hope to see some Sakura if in March
Day 12 Back to US

1st time doing this, does this itinerary looks too tight?
Also can not find miles saver business class from Auckland to Tokyo and then US.