Do not confuse real taxes and carrier surcharges. Real taxes are the same for all airlines flying the same route/class of travel.

You can earn Qantas ff points and status credits (SC) on all Oneworld airline, subject to rules.

• Some partner flights can earn nil or far less than you expect
• For example D business class on many MH flights will earn as flexible economy, and not business--> " Flights booked in C, D, I , J and Z class will earn at Flexible Economy Frequent Flyer Earn Category, however will receive Malaysia Airlines Business Class service, and flights booked in A and F class will earn at Flexible Economy Frequent Flyer Earn Category, however will receive Malaysia Airlines First Class service"
• A code share can earn more or less than the native flight.

QF link--> https://www.qantas.com/au/en/frequen...ry-tables.html
The QF partner earning is *very* poorly presented and hard to establish what you will get. No doubt that is deliberate.
QF has a poor FFP.