As for whether one should call premillennial dispensationalism a form of Christianity or not, this is controversial. I know that most liberal evangelicals prefer to say it does fall under Christianity, but I think that is just because of the liberal predilection for inclusiveness. You should remember that fundies do not consider non-fundamentalists to be Christians. Thus, I think the tables should be turned on them.

I do not deny in the least that there are significant Puritan influences on evangelicalism taken broadly (the latter derives from the former, as far as I am aware) which, among other things, gave rise to the revivalist movements.

A bomb, H bomb, Minuteman / The names get more attractive / The decisions are made by NATO / The press call it British opinion -- The Three Johns