I never noticed any of the stuff you mentioned; I guess I didn't read it carefully enough. I considered him to be a reliable narrator, and what he says he experienced happened. But I think I am often on the opposite side of a lot of those vaguely-interpretable books, like I say that at the end of 1984 Winston isn't really killed, and it's more a metaphor of being fully brainwashed. (Uh... spoilers by the way.) But back to Slaughterhouse 5, I think if I had read it like you say it is, I probably would have liked it more. I felt the alien abduction stuff was completely jarring and disjointed from the war stuff, and it would have made a lot more sense to me if I realized at the end that he was an unreliable narrator. Probably would have made a better book for me. I like books with psychological elements like that. Now I feel half-obliged to re-read it and see if I like it better. :/