Oh R’lyeh?
When it comes to fiction and magic I avoid it like the plague. Fiction does not equal myth front. I have even gone so far as to ban discussion of fiction based magic in my groups.
Lovecraftian stuff is actually one of the FEW exceptions to this rule. Not because its great fiction, but because so many sense the hand of something real behind it.
Do i believe in Literal Chthulhu, Nyarlathotep, or others? Emphatically NO.
I do believe that an understanding can be gained by skilled contemplation of these? Yes. Maybe.
Here is the point I want to make:
Rather than Mythological themes that get represented all over the world through the lens of different cultures and histories, R’lyehn spirituality, if there can be said to be such a thing, seems to point to themes that are NOT AT ALL represented in world Mythology, and can do so because they are free of the different cultures and histories that other myths have passed through.