Da, perhaps I am not aware, but where does it say that thee baal shem went to shomayim? How is learning with Achiah any different than learning with Eliyahu?
As for saying that moshiach will come; many say he was referring to spreading avodas Hashem, and that the baalei mussar accomplish the same thing, which is why around that time, chasidim didn’t attempt as much to gain adherents anymore.
As for having hisnagdus… Many gedolim did too, including the rambam, whose seforim were burned, rav yonasan eybeshutz, etc… Having detractors, even the stature of the Gaon and tzlach, doesn’t mean that you’re wrong.
And it wasn’t all of the gedolei hador of that time, either.