Wow, I really need to read the Chronicles of Narnia. CS Lewis never ceases to impress me. This quote you give from "The Voyage of the Dawn Treader" actually reminds me of something that happens in The Book of Mormon. There is a man who is known as the brother of Jared. His faith was so strong that Christ appeared to him. The connection, however, is in what manner Christ was revealed to this man. Here is a quote from Ether 3:20 - "Wherefore, having this perfect knowledge of God [which came by the brother of Jared's faith], he [Christ] could not be kept from within the veil; therefore he saw Jesus; and he did minister unto him." This suggests that Christ was "required" to follow "his own Rules" (or the laws of the Universe, as was mentioned earlier) and appear unto this man because of his exceeding faith. I just thought I'd like to share that connection.
Onto Brandon's works. Every time I read through one of his books, I find at least a few connections with LDS beliefs. I have no idea if he intentionally places all of the connections I find in his books, but I'm sure a few of them are intentional. I'm pretty sure most of the connections already mentioned here were intentional.
Right now I'm a little curious about the connection between the physical realm and the spiritual realm and the connections with LDS beliefs. Part of why it is interesting is that there isn't too much doctrine on the spiritual dimension in the LDS religion. Albeit, there is more than most religions, but still not much. Joseph Smith mentioned that Spirit is matter, it is just more refined than "normal" matter. It was mentioned by Brigham Young that the spiritual dimension (Also known as the Spirit World, or paradise and prison. This can kind of be equated with most other Christian beliefs of Heaven and Hell.) was here on this earth, not in some other area of the universe. That's about it.
There are, however, a lot of non-doctrinal beliefs on the spiritual dimension. One such belief, held by W. Cleon Skousen, was that each physical atom, or particle (perhaps even quark... I don't quite remember exactly), is paired with a "spiritual" atom. That "spiritual" atom is what gives the physical atom life. Motion, creation, destruction, thought, virtually everything happens because of that "spiritual" atom. Well, here is a quote from the "Emperor's Soul: Devotion's Body" thread in the "Elantris and Emperor's Soul" forum.
It seems that Brandon may have a similar belief to Brother Skousen. He may have even heard that talk given by Brother Skousen and thought it would be cool to include part of that in his cosmere magic system. Thoughts?