Oh yes, there would be a lot of soldiers needed. There were many projects going on just to try and alleviate the need for all the soldiers. Super mutants, Robo-Scorpions, Nighstalkers, Stealth suits, Robo-dogs, spore monsters, Liberty Prime, etc.

Dont forgot my personal favorite crazy idea, creating Deathclaws to replace humans during close combat search and destroy missions.

Hard to forget them! They did get Deathclaw mind control working as evidenced in 3, but they didn't get it done for the Nukes dropped. If only they would have!

Just posted a new thread with final predictions for tutorial. Link in OP, also below.

http://www.gamesas.com/topic/1520864-fallout-4-tutorial-theory

I don't think you having a spouse is likely.

Mainly because there are too many variables: doing a simple gender switch is easy, but what about people who want to play homosixual characters which Fallout has enabled previously? Think it would go against player choice.

Check out the description I have given in the OP of http://www.gamesas.com/topic/1520864-fallout-4-tutorial-theory thread regarding possible character creation. Even if this is not the method that Bethesda have employed, it shows that it would at least be possible to incorporate same-six couples within the pre-war segment of gameplay. The post is a little long, but it should hopefully answer your question

Apart from the character creation side of things, it looks like I managed to get pretty much everything else right with my theory. Just goes to show how much information was really in the trailer!