re the term nasi .
The problem is not so much the term nasi [although I do see a problem as it is more elevated than the term rebbe or admor which is used in other circles]
Rather the problem is the word which is mentioned after the term nassi :
NASSI HADOR
the whole generation ….
Cannot remember the whole generation getting together and appointing the leader of the habad hasidim as Leader of the Whole Generation ….
What really happened – was the following : Habad hasidim [a small minority when using a worldwide Orthodoxy perspective] , crowned their leader as nasi over the overwhelming majority of Orthodox [non habad] Jews who did not even have any voting rights …..
You can give it any name you fancy . I would call this “Cultural Imperialism”.
But in the greater scheme of things , this is understandable [and even logical] .
Think about it .
If your end goal is to get all Jews to accept your leader’s messianic position , you have to first prepare their psyche .
First let them get used to calling him Nassi hador . Nassi of EVERYONE.
The next step – the messiah of EVERYONE , is not such a big unsurmountable step anymore …..
Food for thought …..