I mean I guess the idea of the 7E7 project was fulfilled with the 787-8, but with what it can do, and some of the changes made to it from the -8 it’s hard for me to believe that range wasn’t at least a consideration when it was designed, honestly how incredible is it that any aircraft can get people literally half way around the world in less than a day in relitive comfort. What a time to be alive…
As for your other questions I did a Pittsburgh to Sydney flight a while ago, very similar, and I finished with 1+ hour left in the tanks, I don’t remember exactly how much, but it was enough to be comfortable, that was with the 787-9…
I’ve done NZAA-EGLL in the 789 before. It got super close on fuel cuz I had to go around due to opposite traffic.
The real range MVP in IF is the 763 though lol (literally anywhere in the world, I did WSSS-SEQM once)