1. I can't speak to any technical aspects of the flight.
2. Boeing and American had a little "disagreement" in the late 1990s about the 777NGs. American opted to used RR
powered 777s, Boeing made GE
the exclusive engine provider on the -200LR and -300ER.
To show it's unhappiness, American went and signed an MoU with Airbus for A340-500s, which are, as we know RR
powered. Of course this was nothing more than a PR
stunt, and it was nearly a decade ago (Singapore Air Show, 2000)
With that said, American ought to have followed in Delta's footsteps and ordered the -200LR. There are several routes in the network that could use it (Dallas-Hong Kong, Dallas-Dubai, Miami-Johannesburg, Chicago-Mumbai, etc...). It would add a new fleet type and require a new maintenance program for the GE
Yes there is a chance, it did get much smaller when they ordered the 787 IMO. There is also a chance of snow in Los Angeles from time to time. Who knows.
3. Well, it's (still) flying, something that can't be said of Nagoya, Osaka, Moscow (year round), and Beijing.