Preamble [from "The Mask And Mirror" liner notes]:
November 26, 1993 - Idries Shah on Rumi: "the union of the mind and intuition which brings about illumination, and the development which the Sufis seek, is based upon love..."
March 20, 1993 - spent a wonderful evening at a "café" in the middle of the desert [...] ...two brothers had created an exotic oasis with their families, palm trees and wheat patches...it felt like a settlement of Eskimos in an expanse of snow. We had been there in daylight and they invited us back to hear their music, but when we returned in the evening, we got lost trying to find our tracks among the many in the sand. We saw some lights ahead; the brothers were on top of their roof waving lanterns, signalling us home.
Getting to the point:
1) I believe the first 6 lines of the songs are mostly descriptive; Loreena paints the background of her spiritual love experience. The "voiceless song" makes me think of a melody played from a distant place, one you can harldy hear, ...or maybe it's just a song in Loreena's mind, like a mysterious call from another dimension (I'm not thinking of a "god" in particular - I'm not tied to any religion, I'm "spiritual" rather than religious), or the memory of the one she loves, who is not with her in that moment.
2) & 3) I think Loreena's heart is longing for love, for that "union of mind and intuition", of rational and instinctive, that a person can reach through love - I like to think she refers to "love for another human being" rather than "mystical love". I like to think the "mystic" of the title is
not an hermit isolating himself from the world to reach a deeper knowledge of his god; I imagine it as a person who is "blinded" (which, somehow, is a synonymous of "mystic") by the light of love (both physical and spiritual love = human love).
4) & 5) I always connect the second strophe of the song to the words Loreena wrote in that note, dated March 20, 1993. Lost in her tangled (the reference to the ivy) mental/spiritual journey, some signs intervene to call her back to earth, to reality: I believe the eyes are the ones of the figure in the painting, which she can see only after "extricating" the ivy and the emerald moss (whose eyes are they? Maybe the ones of her beloved one...); the lamps, like the lanterns of the two brothers, are the most evident sign of the finding of a path to follow (= the path of love).
The first strophe in the song refers to a spiritual dimension; the second is the one where the passage from spiritual to material takes place; the third is extremely physical ("I feel you move... every breath is full"). She can imagine embracing her beloved one despite the distance that separates them.
That's my interpretation of the song (sorry for being sooooooo longwinded and prolix... forgive me

).