And about predicting the future, it does not always make someone a Prophet. For example I can predict that the price of oil is going to be over 200$ a barrel in a year from now, but that does not make me a Prophet (if it comes true). One would have to see the exact words of the L Rebbe, and if what he said was totally unpredictable and yett he was able to make the predictions precisly, and even with that it is not enough, because their are also people who know these types of things, yett are involved and get it from Tummah. OR even some religious people who can read hands, faces, etc. but it is a science and does not necessarily prove one thing or another.
+ About the lubavitchers learning about Moshiach, thus qualifying them more than anyone else on the subject as you said- as I and others have seen- they first believed in the L Rebbe to be Moshiach and THEN looked at different sources in Torah to try to make the picture fitt, it is not different then the xtian missionaries who try to prove that yeshu was the messiah, by bringing Jewish texts and reinterpreting them to fitt their belief.
+ maybe not only to do with the Lubavitch issue, but something even broader- do you know what the RambaN said about a Rabbi or leader who makes people be in Awe/ Fear of him instead of fearing G-d and being in AWE of G-d? He said that that Rabbi will go into the deepest HELL and wont ever get out, if what he was doing is get people to worship him instead of G-d (im not pointing fingers, nor am I in the position to judge anyone, BUT this should at least be a cocern for people and expecially the leaders who are given all this Kavod).