Still a lot of veering off topic. You don’t need to get into any hoshkofo issues really. What is or isn’t avodah zara is a Halachic question, so you need to be able to answer it in halachic terms, not just chassidus or kabbalah.
The only question that is relevant, and needs to be addressed is what the Lubavitcher Rebbe meant in the sicha the OP was alluding to. So please, in simple terms, 1) Is betten the same thing as tefila? 2) If not what was the problem the Rebbe was trying to address by claiming that his father-in-law was special and distinct from other Jews in that he was “Atzmuso uMahuso araingeshtelt in a guf?” 3) If betten is tefila bring us a source in HALACHA for why this is not avodah zara, while tefila to other human-beings is.