What makes this hard is sometimes there really is something that is an important value--like going to Israel and serving in the IDF. It is just hard to make sense out of it all with so many cults out there.
It is perfectly possible to learn from Reb Nachman and say the Tikun Klali [ten pslams to say if one has done some sexual sin, psalms 16, 32, 41, 42, 59 77, 90, 105, 137, 150] and even go to Uman for Rosh haShanah, but not get involved in Breslov, but rather to remain in a straight Litvak yeshiva and to follow the path of Straight Torah--the Gra and Musar.
It is also possible to appreciate the importance of "devekut" (attachment with God) and to stick with straight Torah.
But that is not what usually happens. it is just to easy to get caught up in bitul Torah. And Bitul Torah does not simply mean wasting time what could have been spent learning Torah. It also means anything that causes one's fervor for Torah to slacken and weaken.
One aspect of things was brought up to me -the fact that the Litvak path tends to be dry. People can be interested in Reb Nachman for perfectly good reasons--as in looking for the inner meaning of life and the Torah. That is not to say that in everything where people feel taste and and vibrancy is from the realm of Holiness. But I would have to say that in the case of Reb Nachman, it is true that he was a true tzadik and his lessons and ideas are valuable.
One of the difficult aspects however if that of בל תוסיף that is not to add to the commandments. This is prohibition in the Torah and it means that what the Torah forbids is forbidden and what the Torah commands to do must be do. You can not make up new rules and claim the Torah holds that way. And this is the practice of the religious world to transgress this on a constant basis.
[I should mention that I do hold with the Rambam opinion that Physics and Metaphysics are included in the Oral Law. Not just because of seeing this in the Rambam,and the Musar book the obligations of the Heart, but also from my parents emphasis on the natural sciences. In fact I have a new way of learning Physics that I do which is the same way I learned gemara for many years-that is just to say the words in order and go on. In Hebrew that is called "Girsa." That is how I think Physics ought to be learned. But I know it would be hard to convince people of this idea because they do not see every word of Physics as a mitzvah as the Rambam's opinion. If they do not hold that every word is a mitzvah then how could I explain to anyone this idea of just saying the words and going on?
[Though the Rambam specifically referred to these subjects as understood by the ancient Greeks i feel Physics today and also Kant and Hegel would be included. But I also would include the Ari, and the two major commentaries on the Ari, Rav Yaakov Abuchatzaira and Sar Shalom Sharabi.