I currently have a rtw beginning in JNB, issued by Mindpearl but booked with the US AA rtw desk. It has SYD/LAX in May on QF and LAX/JFK in June on AA. When I called the US AA rtw desk and asked them to switch the June LAX/JFK flight to QF they refused, after consulting tariffs, and even documented the refusal in my pnr. Can anyone suggest any recourse to this apparently erroneous ruling?

Are they consecutive flights (ie SYD-LAX-JFK, with a stopover?) This should be valid, but if you have other flights in between, it won't work, AFAIK.
Check that there is availability in the appropriate class on the day you are looking at, and if so you might have to try the RTW desk again and discuss, asking why they can't do it.

Somewhat to my surprise, LAN.com offered QF107 on an otherwise all-LAN booking for EZE-LIM-LAX-JFK-LIM-EZE. Everything priced and reserved without any hitches. Although I have not purchased yet, as my plans are still not firm.

From this thread, I'm worrying that in spite of a seemingly valid ticket that would be issued by LAN, QF would refuse the confirmed reservation all the same. Seems quite strange to me that they could do so. Any more data points on this?

Yes, QF has often refused to allow passengers to fly the LAX-JFK segment in this situation.

Syd-jfk/jfk-lax?
 

I previously posted this question but no one managed to provide an answer.

I have an AONE5 where I will fly F SYD-JFK on QF, then stop. My next sector will be JFK-LAX on QF. Since my transpac sector is on QF, will QF JFK accept me on the JFK-LAX sector or boot me to AA?

See post #30 of this thread ... Of course YMMV.

I believe this scenario is fine as you would have done the Transpac on QF before the N/A transcontinental. There has been a mention that one could do QF108 JFK-LAX with a subsequent transpacific on Qantas in the booking but later changed ...

Does anyone definitively know whether the QF trans-Pacific flight needs to be both on QF metal and a QF flight number?

We're currently booked SYD-LAX on QF metal and the next day on QF 107 from LAX to JFK (all one DONEx itinerary), but the trans-Pacific is currently ticketed as the AA code-share (i.e. AA 7363 instead of QF 11). AA's RTW desk helpfully assigned us seats on both flights, and no-one said anything about having to fly on AA metal on the second flight....but should we be prepared to be bounced by Qantas?

In circumstances of being bounced off the QF flight, does the QF check-in desk at TBIT assist regarding AA alternatives, or is one simply rejected and told to go away?

As reported above, when I got bounced QF called my TA one day before and they had already protected me onto an AA flight with very similar timing.

Just took QF 107 from LAX-JFK last week.. I was on a AONE5 ticket.. I had gone from SYD-LAX, then did a LAX-ORD-LAX turnaround on AA and THEN did my transcon on QF107 to JFK.. All sanctioned by the AA RTW desk.. NO PROBLEMS in boarding... just for your information...