Glad you're liking it so far! And similarly, I'm happy to share my understanding of the lore around my plot decisions with anyone curious. Not to overshadow your offer, guiden, just the lore as I understand it that guides my storytelling and the official canon are not always the same!
No offence taken here, I just love talking about 40k stuff, in fact it's the way I met with the guy who is now one of my best friends. I recommended this new campaign to him by saying that one member already took himself to zero hp with his own chainsword before any combat was even close, here's to your continued good luck Kevin
40k leaves a ton of stuff vague on purpose, from the two lost Legions to the true plans of the Harlequins. What I'm interested to see is what you will do with the non-imperial remnants the explorers are sure to find among the Heathen Stars. These kinds of societies are always mentioned in the Horus Heresy stuff or as footnotes in codex but are not often explored in depth. I liked the hints of a creation myth on the murals. I'm guessing the building looks like a cathedral because that's what humans had been building for ages past?