Temporarily summing up the Kajiuran part, I can't help saying I'm positively shocked! If these words have meaning, that DOES put Yuki in one league with Mr Tolkien! :D
"to nowhere" mostly covers the dialogues between Tsukasa and Subaru. I suppose it is meant to express Tsukasa's state of loneliness (like "a stray child"), but with the smart difference that he isn't really alone now. He's got another lonely soul by his side, to hold on to and to go ahead together.
Btw, did you notice that in her english lyrics, Yuki often uses the contrast of Light and Darkness? Darkness is often where the characters start out and Light is the destination, the target of the search. (and to think how it matches the mood of Mashimo's directorship! XD)