PaxVenire
Wasteland Peacemaker
When you even consider throwing out the main characters in an adaptation, maybe take as a hint that the thing is maybe unadaptable. This is like trying to adapt a Superman story, but you consider not even have Superman in the story.
This is a horrible comparison to make when you take more than 3 seconds to think about how Fallout isn't directly about one sole character, but rather about themes such as the consequences of nuclear war, abuse of technology and playing God, ethics and morality in a post-apocalyptic world, and the predictability of human nature to wage war no matter the circumstance just to name a few.
Superman is a superhero. His comics follow his adventures alone and revolves around him saving the day from evil and corruption, and generally being the beacon of hope for the people. Fallout is not comparable, and comparing any of the main characters to Superman is quite ridiculous. The main characters of Fallout 1, 2, and New Vegas are vessels you make to introduce you to a different set of conflicts, settings, and narratives. As a matter of fact, aside from their titles of the Vault Dweller, Chosen One, and Courier, the character is quite literally a blank slate, because the world's existence doesn't revolve around your character, although through exploration and engagement with the world, your character you can shape it.
And the thing with the Enclave and BoS is they shouldn't have been in Fallout 3 to begin with. Those are two of the major things that make the story of Fallout 3 unadaptable, these factions had no business being in the East Coast.
Again, this is something the fans can bitch and moan about all they want, but no one in Hollywood or the general audience will care. I agree that Fallout 3 lazily recycled everything from the first two games and inserted them in a way that's forced and uninspired for a new entry in the series. But staying on the topic of strictly adapting Fallout 3 into a film format, it's still very much possible and if need be can be tweaked because that's what an adaption allows. Especially for a series as flexible as Fallout.