Concerning the first point: The military was not involved it was a mercenary force funded by a major corporation. Think Halliburton, not US Army.
Yes, the forces weren't overtly the US military. ... Just like Halliburton or Blackwater (don't they have a new name now since they're so hated?) aren't really used by our government as de facto private armies that break laws and get their hands dirty in ways our military doesn't feel comfortable doing?
I don't want this to get all political, but there's no denying rationally that the forces represented are basically US. And that whether its a government's military or just an evil corporation, those are things that much of the WDW-going base loves. James Cameron, make no mistake, does not.
But again, I'm sure this will be glossed over like it doesn't exist.
This is Disney, the company afraid to release Song of the South (while releasing Dumbo, with similar racial sterotypes) that still uses its characters in its parks and as the centerpiece of E-Tickets in Orlando and Anaheim. They'll just pretend -- and that's fine. I just thought the point needed to be raised as it's legit.
Also the plot of the second and third movie may involve the humans working with the aliens against a common enemy or attempting to bring balance back to the planet.
No idea about the plots of the upcoming films as Cameron has kept pretty tight wrap on things. Who knows? But the only film we have to base opinions on is what exists. And it was evil white American-appearing military folks attempting to pillage a peaceful society for its resources and/or kill them all so 'we' could steal them. Not really a message in living in harmony with nature, even on another planet in another galaxy etc.
As for the second point: they could easily address this by placing a bunch of solar panels on the roof of the large space and maybe even add some themed wind turbines (the base has to get power from somewhere). So they could kill two birds with one stone here. Actually providing power and getting a little credit for being "responsible" which again ties into the storyline.
I think what you'll see is one giant soundstage type building or multiples. And I don't think Disney will go green while going blue.
But we have years to wait ... many, many years!