Avira,
I can tell (I knew a long time ago) that you are not chassidish from any chassidus.
Ask a satmar chossid who “the rebbe” is, and he will tell you the satmar rebbe.
Ask a gerrer chossid who “the rebbe” is, and he will tell you the gerrer rebbe.
Ask a belzer chossid who “the rebbe” is, and he will tell you the belzer rebbe.
Ask a bobover chossid who “the rebbe” is, and he will tell you the bobover rebbe.
Ask a breslover chossid who “the rebbe” is, and he will tell you the breslover rebbe.
Ask a sanzer chossid who “the rebbe” is, and he will tell you the sanzer rebbe.
Ask a vizhnitzer chossid who “the rebbe” is, and he will tell you the vizhnitzer rebbe.
My point is, that lubavitchers call him “the rebbe”, because he is our rebbe. He is the closest of all the rebbes to us, and to us he is the rebbe, he is our rebbe and that’s my rebbe. And since he is our rebbe, we believe that he is the rebbe.
And to a belzer chossid, the rebbe is the belzer rebbe, and he is “the rebbe”. And he is the rebbe, more important than all other rebbes, because he is their rebbe.
Think of it like this: Your rosh yeshiva, you have much of a closer relationship with him than the rosh yeshiva of a different yeshiva. In your mind, he is “the rosh yeshiva”.
It’s not so hard to understand.