Since you’re not asking a question, but giving me a lecture, I don’t really feel like you’d take any answer seriously. Nevertheless, i will respond. Comparing mussar to chassidus, and especially to kaballah is fundamentally flawed. Chassidus is not a replacement for mussar, and learning mussar does not patter you from learning kaballah.
The Baal HaTanya says that as the generations have gone on, people need additional things to maintain a kesher with Hashem. He says this is the reason that the earlier tannaim sometimes davened very quickly, a portion of shema and that was it, while for us, we need pesukei d’zimra and all of the tefillah to do a proper hisbonenus and maintain a kesher with Hashem. As the generations have fallen further, it is completely understandable that people would need to learn more chassidus and kaballah simply to maintain a kesher with Hashem that the earlier generations (and you, obviously) take for granted.
the Arizal already stated that the main avodah in our generation is tefillah, more so than Torah, even though talmud torah k’neged kulam. This is the reason. All the more so in our generation, where we have fallen to the depths of the kelipos, that without learning nistar, we are at even more of a disadvantage against the kelipos and tumah.
Now as for the gedolim question, as I have already said, the gedolei hamekubalim are of one mind that the kaballah was passed on from R. Shimon Bar Yochai, elucidated by the Arizal (and decoded by the Baal Shem Tov) specifically for our generation. If you want a brief overview of the topic, check out R. Daniel Frisch (the baal masok mi’dvash) sefer shaarei zohar which gives a brief but compelling summary of the topic.
As for your quotes from Shulchan Aruch HaRav, that sefer was written much earlier in the Baal HaTanya’s life, and includes significant differences between what he held at the end of his life. I am not saying that the Baal haTanya would say that people should spend all day learning chassidus; he would not. I’m just saying that you cannot bring a definitive proof from this.
Now, if you want to ask an honest question, let me know. But please stop lecturing and calling me a halacha-breaker.