Excellent perspective. In rereading, I can't quite tell if the ritual was a Chaos cult, as described by Hoji, or if it was some off-the-map Flesh Eaters ritual being led by one of their more out-there Chaplains... although from the description, it does sound more like a Chaos Space Marine leading the ritual on first read.
I like how you're casting the Alpha Legion as the defenders of humanity, although most of the prior descriptions of the AL Astares has them festooned in spiky bits or at least showing some sign of corruption from Chaos.
The White Zone is for loading and unloading only. If you have to load, or if you have to unload, go to the White Zone. You'll love it... it's a way of life.
: Cigarettes in space?
: It's the final frontier, Nick.
: But wouldn't they blow up in an all oxygen environment?
: Probably. But it's an easy fix. One line of dialogue. 'Thank God we invented the... you know, whatever device.'