I believe Rumpel can see something of the future. I rewatched the pilot again the other night with my husband who is starting to watch because I talk about the show so much. In the cave when Snow and Charming visited him he seemed to have to work hard to see the future — he squinched his eyes and screwed up his face in an effort to see that it would be on her 28th that she would save them. He didn’t know that by normal means. Snow wanted to go to him because she believed he could see the future, she says so. So, I would say he sees some things. I don’t know if he can see everything. Maybe just enough to manipulate, or maybe what he tries to see. If he doesn’t try, he doesn’t know.
And I do remember Rumpel/ Mr. Gold saying something about emotions “blinding” people from seeing clearly. I think I have seen that more than once, like someone else said it… maybe Sydney