Dear Avram,
“.. on par with Avodah Zarah or not.”
A”Z is not the same as minus.
There is no A”Z here because there is no worship other than going to the ohel. Which is no different than going to any other kever.
Saying yechi, even including divine identifactions for the rebbe, is never A”Z. It would only be minus with an overall context of a new order. (Order as in teaching, belief, dogma.)
The easiest way to test the boundaries of klal yisroel is to become a mumar. This can’t be applied to Chabad as they are as observant as the rest of us.
I have pointed this out dozens and dozens of times. Every poster here seems more interested in piling on Chabad for the sillies things, than responding to how they understand these basic concepts. I have come to accept that pettiness is their highest dogma.
Maybe you can forgive me for having the opinion that yidden don’t care at all about what it really means to accept the Kingdom of Hashem. They prattle about it a bit for Rosh Hashana and can’t make sense of it. So they move on to the rest of their year. The individuals who seem to understand it, don’t really discuss it. Maybe this was what Rav Soloveitchik meant when he said that it is something to experience and cannot be taught.