The importance of learning Torah and the basic message of Musar which is Fear of God and good character traits you really only get with the path of the Gra. The path of Rav Nahman does not really have "hatmada" to be learning Torah constantly as an essential part of it, not the sort of basis of Musar. You get other great things in the advice of Rav Nahman but not those few points which really relate to the Gra. 

And I see these points of the Gra as being the essence of Torah. Diligence in learning Torah, Musar and fear of God in the way described in the books of Musar and not to speak lashon hara [slander]. To me it seems that without these points that nothing else can even begin. Sine que non. But if you have the Gra, then there is tremendous benefit in the advice and ideas of Rav Nahman.

[And I admit that my idea of expanding the idea of learning Torah to include Physics is not really part of the path of the Gra though it is hinted at in other rishonim. Still it seems to me that everything has to start with the Gra. The Gra is sine que non.