I don't think the "revolt" is necessarily Pagan.
I personally think the rebellion of the Angels was the standard Jewish opinion of who the "Sons of god" were who interbred with human women since the tradition began and this understanding only changed much later as Rabbinical thought developed.
The idea of Angels not having Free will I think is an unfounded, Rabbinical concept which disregards and ignores passages that say that God will punish even the host of heaven. Why would he punish them if they had no Free will?
With that said, I think Ha-Satan may have indeed "fallen like lightning" from an original post of being the chief archangel or something like that as the Gospels describe, but is still nonetheless the official "Tempter" and "Accuser" who is responsible for the condemnation of people for their sins, and even though I disagree with Paul and his epistles, I agree that he is "The god of this age" (2 Cor 4:4) and the "Prince of the air".
I also believe that he is the "Ancient Serpent" of Revelation which correlates to some ideas in the so-called "Gnostic literature" of the Chief punisher and adversary of Man. But Ha-Satan is not really the "enemy of God" in that he cannot do anything that God does not allow. Even the rebellion of the Angels I believe God allowed, as a test as well to the human women who shacked up with them, even if it brought mankind to such evil and wretchedness by teaching them of the forbidden arcane arts, because it was all part of the testing part for the individual souls of man.
*My view is also as a born-Jew who became "Messianic" (I prefer the term Nazarene though its still not the best fit as its a bit presumptious to assume myself as one), and I held very similar views regarding Ha-Satan, fallen angels, and Demons before I became such. I believe the Book of Enoch was in fact inspired, perhaps not written by Enoch himself but dictated by Enoch's spirit as outlined in the book "Pistis Sophia".