A Tolkien-Broster comparison could be interesting... yes, as hyarrowen has pointed out there's the Oxford connection, and I think it's likely he was at least aware of her as a writer. (Apparently Tolkien also knew and admired the work of Mary Renault, who was also at Oxford around this time—which surprised me a little!—but I really wonder if Renault and Broster knew each other's work. Although Renault's historicals at least are a bit too late for Broster to have read them.)

(While writing this I got side-tracked and saw that apparently some people are trying to get Tolkien canonized?!?)

o_O

Is it just me, or does this sound kinda Catholic?

I thought so too! I suppose, as well as the Catholic-ness of Episcopalianism, there's also a connection between Catholicism and folk-Christian beliefs, which this sounds like.

And good points about the scene by the loch—it is indeed beautiful, and yes, that 'sacramental' is significant (like Ewen's grief that he won't see the places he loves in heaven, it's not a typical/orthodox religious belief, but one that follows very naturally from Ewen's character and the place of faith in his thought, and works very well as part of the story).