Welcome to the forum:

You will not get a OW quote without a valid routing. The additional taxes & fuel surcharges are very variable. Depends a lot on the first carrier and exact route (avoid LHR if you can)

For route testing have a go with MM http://www.slfft.org/mm/award.htm
Written by FT'ers. Is not always 100% perfect or with all routes but a good starting point

NRT-BKK-AKL-Buenos Aires-SFO-Paris-HKG-NRT
needs to be something like
NRT-BKK-HKG-AKL-SCL-EZE-DFW-SFO-LHR-CDG-HKG-NRT (click blue link)

It is hard to get D or L ticket on the LAN AKL-SCL flight. Look at QF code share or SYD-SCL on Qantas