Answer

As I understand it, it is a collection of spiritual intuitions, some of them good and useful. It seems to me that there is no real indication that this was given from above at any stage, and therefore it has no authority, though there is certainly something to learn from it. In short: respect it, but suspect it.
Usually, when something is called “Kabbalah,” that is a sign that there is considerable doubt whether it was really received and accepted from above. Just as names like “The Union of the Groups and Kibbutzim” or “The United Kibbutz” are a clear sign that the main thing missing there is union and unity. Likewise, a study hall that constantly talks about tradition and the prohibition against deviating from it (like Brisk) is a sign that their approach does not have even a shred of source in the tradition. And similarly, a study hall that constantly talks about the importance of attending upon genuine Torah scholars (Har Hamor) is evidence that they too are inventing their path out of thin air and have no real source in the tradition. And in the books of Chaim Grade you can see that Tzemach Atlas, who is constantly hounding anyone who has forbidden thoughts and desires (heresy and urges), actually suffers from these himself (in contrast to the Chazon Ish, who was completely calm in his attitude toward such phenomena), and there are many more examples along these lines.