If you think the existence of magic doesn't affect religion and belief, then that alone makes it useless to discuss this with you. As for creation, there is one in the third Mistborn book, and the "God" even writes a book about it. Then, if you look closely, anyone who worships a "God" in Mistborn really worships the power from the shard, which isn't an actual entity, since it follows the will of whomever wields it. So that could be considered non-theist in itself.
I'm not sure what the point of this thread is. Are you offended that you don't find a lot of the religion you want? Do you think it is misleading or wrong for it to not be explicit in his fictional universe where you only see the smallest portion in each book?
That'll be my last contribution to this thread. I hope you got what you wanted out of it.