For the Dwarves, I'd say look to this Inner Earth as a Mother Deity. Perhaps great forces of evil, or some leak between planes tainted and corrupted the Inner Earth so much that the Dwarves were forced to dig their way out, all the way to your world. And hey, maybe now they try and make sure none of that darkness from their home can follow them back, keeping them in the mountains. Either way though I think a Mother Earth sort of divinity is a cool fun spin that may work for you.