Absolutely no incentive for MEL based QF passengers to fly on these Sunrise routes. Sydney is one of the WORST airports to transit Domestic to Int. If I'm therefore having to break up the journey, I'd rather take a SIN stopover on the way to LHR or AKL on the way to JFK.

One key one that you've missed here is US Global Entry. While it's not available for AU passport holders, but for those with a UK (or a few other) passports, you can apply. The process is a little involved (includes an interview at a Global Entry office), however, for $100 for 5 years, including ...