I need some clarification about the AAdvantage challenge. If I were to do it, all the flights that would count would need to be AA####. I couldn't be flying on QF####, operated by AA. Is that correct?
Yes, you would need to book the codeshare, the AA#### flight, not the QF#### flight. The AA codeshares are typically slightly more expensive than the QF marketed flights. However after you complete the challenge, you're free to book the QF marketed flights and credit the mileage to your AAdvantage account.