What was Marlton doing in the Fallout Shelter?
He said he had a lab of some sorts. Maybe that's his lab?
What's the status on the O3 from Moon?
They're probably dead.
How was Samuel able to hear Aether voices in Die Rise, but not in Buried?
The voices originate from the Zombies, moaning things like 'kill me, help me'. I think it's because they only died recently. As the Zombies in Tranzit and Buried have been dead for much longer than the ones in Die Rise.
That or it's because their moaning was simply too annoying.
What are the background stories of the N4?
Russman - worked at Broken Arrow, knew Stu as a child. Probably got fired. Living on the streets til the outbreak happend.
Marlton - scientist. Maybe he too worked at Broken Arrow and played a role in Russman's departure. ("You've been walking the earth ever since the, uhm, incident" refers to Russman's getting fired. It sounds like Marlton knows an awful lot about it.
Which side of the Black Ops 2 Side Quests are canon? (Most likely Maxis)
Maxis.
What specifically was Broken Arrow?
Never explained. Had some sort of involvement with the oubreak, so perhaps they are a modern 935-ish group studying Element 115 or something among those lines.
How has Russ been living so long and healthy?
He hasn't. He has more deceases than one can count.
What is Russman's real name?
RussMAN!
What was the Purple Light from Die Rise about?
Richtofen's mumbojumbo magic teleportation and restoration skills.
What book does Samuel have during the events of all 3 N4 Maps?
Good question. Probably the diary enteries we've been getting with each new map.
What happend to the Mob Crew?
They're all dead. Stuck in purgatory till they move on.