Who was that other Flash that followed Zoom back into time and was there where barry mother died though?

And could it be that Zoom is trying to make sure that the Crisis event is averted, with barry as the hero, so he preserves both his future, and ends up with Flash dead as he wants in the end?

And are we still certain that wells is really Zoom?

And what if, as anticipated, supergirl somehow gets factored into all of this?