I don't think what Ramban said was revolutionary. I don't know who it is who teaches that Moshiach will be a divine being {except for Christianity}. And concerning the Medrashim which are discussed in the Talmud, as we all know that there is debate between the Rabbis of the Talmud, and we {at least I was taught} have to take from each Rabbi the wisdom which was intended. This wisdom is not always literal, but it is true on some level, and through our understanding we can discover what this wisdom is.
This is why it can be said that Moshiach has already been born, and yet we do not see him today.
The Ramban, in this movie, does say that things will change in the Messianic age. I do believe that things will be quite different, not through physical miracles, but through a basic change of heart of the Jewish people. This change of heart is miraculous, considering how difficult it is to get Jews to agree on anything, and this change will be what indicates that Moshiach is here.
Rambam in this movie says that the era of peace itself will be the sign that Moshiach has come, that when we 'beat sword into plowshare' this will be the sign that Moshiach has come. Mankind has not been peaceful since we were placed into Gan Eden, with one fight leading to another leading to all out war. When the Jews are able to bring about the understanding that Hashem is the ONE G-d who has love for his creations, can the Moshiachs mission begin. I think it will take both our effort, and strength given from above, to achieve these changes.