It seems to me also a lot of places to visit in a short period. It only takes one bad overnight flight, one misrouted bag, or one missed connection to ruin a day, and make your wish you were back in your own bed at home. If you are a road warrior -- you know the game: enjoy it, take those inevitable knocks on the chin. But make sure your travel partner is on board with this plan!

I don't think RTW fares deliver best £/TP. I'd be looking to make everything as comfy as possible, and if I needed more TPs, I'd just have to book another trip later in the year. :-)

I wouldn't sweat it about UK APD. Yes it's £191, but avoiding it by breaking your journey in Dublin or Paris can incur its own costs (extra hotel night, transfers to/from hotel, meals, drinks, separate flights to LHR -- doesn't leave you with a lot of change from £191). So maybe it makes sense to avoid the APD, maybe it doesn't, but don't assume you've saved £191 by doing so.

I'll also add, internal QF flights are very cheap for Avios redemptions. So you may find it more logical to do SIN-SYD-AKL, and book a separate SYD-HBA-SYD ticket on QF using your BAEC points.