Cybertron and its history

Something I've been wondering about for a while now, and I can't seem to find explained anywhere, unless it's buried somewhere in the forum archives. What was Cybertron's involvement with Earth in the twentieth century? Did G1 happen as depicted in the source material, antedating the creation of the WDF and the whole craziness of the early Core material? Or is The Movie (as briefly shown in Cybertron Reloaded) simply adapted to remove previous presence on Earth?

I've not actually read the deprecated Cybertron Dreams, so if this is covered there, my apologies.

Advent of the Norse Pantheon

How did the upper echelons of the WDF come to be involved with the Norse Pantheon in the first place? Did the events of the source material happen, albeit (presumably, I'm not familiar with it, but based on what I've heard...) less bizarrely, at some point? Or is it intended to remain somewhat mysterious?

Thanks in advance.