Does
“being on the ground a little” mean you are now resident in the B of P?
Some to many people come to this part of the world (NZ AU) for a
few years, but are still here decades later.
Flying paid J means you get most of the benefits of mid-top level status. And bonus ff miles/points/avios.
Upgrades are hard to get. Most on the airline of your ffp. In this part of the world airlines will fly with unoccupied PE/bus class seats.
Star Alliance has a cross airline upgrade scheme, but requires a high priced base fare, has onerous t&c’s and useless for most people.
Oneworld Alliance does *not* have a cross airline upgrade scheme.
BA & AA have an out of alliance cross airline upgrade scheme that has t&c’s. May be of value for your USA domestic flights.
Trans Tasman are many options AKL SYD (NZ QF JQ and MU LA D7). Assuming this where you would like upgrades. Some aircraft TT are economy only. Business class varies from regional bus/PE type seats to lie flat. But flight time is only ~3:30hrs and if you can get an exit row – more legroom economy seat. You will survive.
Maintaining BA Silver (OW Sapphire) would seem better than trying for status with QF from the bottom.
Flying AKL-SYD on QF operated BA marketed [codeshare] and then SYD-SIN on BA return will get you the required 4 flights to maintain status. Only need to do once per year (or 2 years?).
Qatar QR also use avios as the frequent flyer currency. Avios, but not status, can be moved between the various ffp’s using avios.
Can earn QR avios on Virgin Australia flights. Before CV19 VA used to fly to several NZ destinations, but now only ZQN.
I would give up on maintaining CX Silver (OW Ruby) status. But NZ & CX have a codeshare AKL-HKG. Credit any CX flights to BAEC, if an eligible fare class.
For your trips to PHL in J many options from AKL. Guessing price will be a consideration. Will need a USA domestic flight or maybe even an Amtrak train from NYC or DC.
Oneworld
Star Alliance
Skyteam
Some of these are seasonable.
And even Fiji Airways FJ via NAN (Oneworld) or Hawaiian HA via HNL. Or airlines via AU. Pricing has little logic or is based on distance travelled.
You may find SYD-AKL, transit or stopover a few days and then AKL-USA in J, all in 1 ticket, is better priced than J AKL-USA.
For EMEA (Europe – middle east - Africa) hard to go past the middle east airlines (QR EK).
EK is a ff partner of QF, JL and others.
Qatar QR ff earning to Qantas QF are poor. Are not the best friends, even though both in Oneworld alliance.