Originally Posted by iwillflytheworld

I don't think this is true. A change of date to any segment other than the first one should not trigger a reprice, even before departure.
Correct.

I also think that changes of routing after departure should not trigger a reprice of the whole itinerary, just the $125 fee, unless a continent is being added.
Correct. But a change of routing (or as the fare rule states it "a change to ticketed points") will cause the taxes and charges to be recomputed.

The rules are explained more clearly in this document: https://www.oneworld.com/images/faqs/oneworldFAQPDF.pdf .
The linked document is a copy of the fare rules from 2018. Well out of date! However the rule on ticket changes is unchanged since then.

Whether you can get a QF agent to actually follow these rules is a different matter.
Agree!

I'm new to this so I welcome corrections.