3. Nothing you can do about it given how far ahead you are flying. Even longhaul routes are not immune to dropping F. At least your final 8 flights (with open or dummy dates) are routes that are unlikely to be dropped altogether so you aren't too exposed to messy rerouting issues (except voluntarily, eg to try to get back into first if a flight drops it).

5. You can book LA flight AKL-SYD (assuming you are travelling on a day that operates) to avoid QF ticketing when using the OW tool. Note you must use the one on the OW website - the link on QF website forces QF ticketing no matter what airline operates the first leg. However, if you use that tool then you cannot have open dates and will need to select dummy dates for everything, and later change them.