(although the phrasing sounded a bit "modern") because my overall impression of Thorin is that, although he's part of that Middle-earth world where magic and prophecies are an accepted part of life, his own personality is very practical and hardheaded.

In AUJ when Oin starts talking about the omens, you can see a couple of the dwarves rolling their eyes, either in disbelief, or perhaps just tired of listening to Oin's prophecies, and Thorin himself seems more concerned about the rumors that are spreading and about someone else getting to the mountain first. Later, when Gandalf gives him Orcrist he puts aside his distaste of anything elvish and takes the sword because it's a good sword, and in Rivendell, although he has to be coaxed and he struggles with himself, in the end he lets Elrond read the map because no one else can read it.

This kind of "just get it done" attitude is pretty consistent in him throughout all three movies and fits in pretty well with the practical Thorin of the LOTR appendices, who told his father that he would go back to blacksmithing to keep his arms strong until the time came to wield a sword again.

When he shot at the white stag the look on his face was pretty unfriendly, so I think he knew darn well he was shooting at something "elvish", but if he'd hit it, I think there would have been venison for dinner.