It really ought to go without saying, but still I think it is worthwhile to mention that the ideas in Rav Nahman's LeM come within a certain context. Thus without a basic background in Gemara and Musar, things that he says often are taken out of context. Thus it is easy to see how when people get involved in the teachings of Rav Nahman, sometimes things go a bit onto some tangent which does not seem to be anywhere near the original intensions of Rav Nahman. 

So what I am thinking is that if one has merited to be in a straight Litvak yeshiva where the context and meaning of Torah is crystal clear then he ought to stay there. And learn the ideas and books of Rav Nahman as an addition to Musar. And if there is no Litvak yeshiva nearby, then to make one.

So what is straight Torah? That is not so easy to explain but more or less it is the kind of attitude that I saw in the Mir in NY which could be summed up as follows: "We have no opinions except what the Gemara says." It more or less is the idea that opinions expressed in the Gemara or Rishonim count as legitimate Torah, Anything that does not fit within that context is out of bounds.