The levels of yiras Shamayim in lubavich are R”L terrible (tznius is one obvious example that has been mentioned, but I can give more if necessary).
It depends which circles you hang out with.
There is absolutely no indication that the Bsh”t wanted limud chassidus (and of course chassidus chabad is for some reason the best) as the yesod of his “movement”.
Well, it’s true that Chassidus Chabad was a Chiddush of the Alter Rebbe (although I do vaguely remember that he tried to convince the Chevraya that Chabad was the true Derech of the Baal Shem Tov, they obviously didn’t accept it.).
But just because we have few Seforim from the Baal Shem Tov and the Maggid doesn’t say much. For example, in Chabad (not just Lubavitch), studying and meditating on “Toras Chabad” is and always was the primary method of becoming a Chossid. Yet, until Lubavitch came to America, the entire printed Chassidus would take up a small bookshelf. It was just that printing was expensive and the Rabbeim wanted Chassidim to work for their Chassidus. You can’t just go to a bookstore and buy a Maamer, you have to go to your friend, beg him for his priceless manuscripts, and make a handwritten copy for yourself. Or better yet, memorize it and internalize it.
But the Baal Shem Tov did spend time teaching Torah, and many of his Talmidim wrote Sifrei Chassidus (like Tzavaas Harivash, Keser Shem Tov, Toldos Yaakov Yosef, Ohr Torah from the Maggid). You think they wrote it to put on the bookshelf and never look at again?
But either way, even if it’s not an Ikkar of Chassidus, there’s definitely an Inyan to learn Pnimiyus Hatorah, as Reb Chaim Vital writes in the Hakdamah to the Shaar Hakdamos. So you don’t want to learn Sifrei Chabad? Learn Pnimiyus Hatorah of other Chassidus, or even non-Chassidic works of Pnimiyus Hatorah (Nefesh Hachayim).