So now that I have quoted gedolim who say that every “yechi” yarmulke is a declaration of apikorsus, and a simple visit to Crown Heights will unfortunately show a very large number of such apikorsus, there can be no reason to entertain a hava amina of joining Chabad, even if they do have a 10:30 shacharis with a sach vodka and shnapps. Avoid the apikorsus. I feel very bad for them, the same way I feel bad for members of the Lev Tahor cult.
A Chabad-leaning friend of mine who was old enough to visit 770 when the Rebbe was clearly alive lefi hakol mentioned the time he was there and saw a few people davening directly to the Rebbe. The Rebbe turned around and corrected them and told them to daven to Hashem instead. While my friend reported this incident in a positive light, all I will say is that nobody “accidentally” davened to Rav Shach zt”l.