He's wandering around. He has a beard. He's doing odd jobs when there is no reason that he could possibly have to do that (atleast no good reason). To me, that screams of him dealing with some Nolan brand angst. Its Nolan's bruce Wayne with more manual labor. He's not just wandering because he likes to travel.
How do you know he is wandering around? The movie isn't out yet and you have not seen it.
There could be a very good reason they show him doing odd jobs. But since you haven't seen the movie and you have already made your mind up there can't be good reasons...that is nothing but circular logic. That shows poor reasoning skills.