Dear Qwerty,
You did not say that, it was a different poster. Now it is two posters. They are not even making an argument. Maybe when they say Christianity, they mean Breslov or Brisk. Okay, Chabad is like Breslov or Brisk.
You say that Lubavitchers treat their rebbe like a god. The Gemara tells us to have awe of our masters like the Awe of Heaven. Both Lubavitchers on this thread admitted that the Rebbe could have made a mistake.
Chabad atributes special powers to tzaddikim and they think of their rebbe as a real big tzaddik. this is not very unique to Chabad. Though they do have more of a thought system for it. If you have a problem with it, take it up with the Sefer Tanya. If the sefer is no good, than go check all the classics and see who agrees with the Tanya. It’s a sugya to learn no different than any other.
My position in regard to Chabad is that there is no reason to analyze their beliefs. Their positions are no less absurd than Satmar or Ger or Skver. And atleast they have a legitimate history of these concepts and can trace the outlines of their ideas throughout the centuries.
Since you are the one attacking, it is on you to explain why it is problematic for people to have absurd ideas. And why we should debate them as if they need to drop it or face excommunication.