Penumbra overall storyline and a few questions?

[TheAlluringDarkness13]

I try to answer your questions as good as I can (sorry my english).
1.Red was a guy who worked in the mine (his actual name was Tom Redwood)
2.I think Philip had sent the message to "us" but I´m not sure
3.I haven´t played Requiem so I don´t know anything about that
And the artifacts (do you mean the save points?) were things that were in the Tuurngait-Tomb and helped the virus to grow.This is what I understood.
I hope you have understood what I wrote and that it helped you a little.