Some pretty good points. Yes, done Dallas but not like Debbie, and even driven past Love Field. I like the idea of a parallel east-west runway at Sydney.
The constraints for future action seem to start off with Sydney Airport ain't closing, ever, which means the alternative really must be in the greater metropolitan area. I can only think of Badgerys for anything likely to be to Sydney what Gatwick is to Heathrow. Maybe as unit costs for fast surface transport systems come down in the future there will be viable alternatives to flying between Canberra-Sydney-Melbourne, maybe even as far as Brisbane. But that is grandchildren stuff. Between now and then I think nothing will get done and spending eight hours driving to Melbourne from here will seem not too shabby put beside a two hour drive into Sydney for four hours of being stuffed around or 80 minutes to Canberra and then three hours of being rooted on the spot especially in winter.