Honestly I think it'd be pretty easy to make it all accessible! The RPG aspects of the game are actually pretty shallow, like these factions could easily be described/explained with short blurbs on some sort of info entry for a DWRP game and you wouldn't have to omit anything that'd be relevant to gameplay to keep it short. Most of the lore found in the game's grimoire wouldn't be immediately relevant to the characters anyway, so it'd probably just be best to set it up as a sci-fi/adventure game with a touch of horror and give players the BG info as they uncover it naturally in the readymade maps and story lines. Obviously you wouldn't want to guide players through the shitty barebones story of Vanilla Destiny but if someone wants to go digging through the laboratories on Venus you could use the Vex experiments as a jumping off point for an interesting mod or player plot.

But like I said a couple replies up I'm personally way too busy to spearhead this kind of thing, I'm just a total nerd who has read every available entry in the Book of Sorrows and would be totally down to help.