Hmmmm, now I'm confused about Dean's situation. I can see his adoration for Ben and that enthusiasm Cas hears may suggest things'll work out. But you also gave us that line 'bout Dean and Lisa not having anything in common 'cept for beer and a t.v show. Will Dean ever go on a life-long roadtrip with Cas later on? IUNO. D:

But yay for guns and cars and things. I know nothing about them either, but for it's worth, nothing stood out to me as being wrong so I think you're good.

Cas can be known later as the badass, sword-wielding hunter who can sense souls and the supernatural. Kind of awkward with technology, but he's old school. >:D