No, he implied it would be his FIL, as that was his Rebbe.
The rest is extrapolation.
Correct. Does that mean there were two moshiachs simultaneously, one for the Rebbe and one for everyone else? And of course more, once you count all the other chassidus's who should also believe the same (according to this hashkafa?)
Or maybe, just maybe, the Rebbe wasn't talking about the actual Moshiach bem David as opposed to a chassidic belief as how a chassid should act (that one should act as if).