I don't want this to be a short review, but there's not a lot I can say.
Definitely keep this acoustic, It works so well with the vocals, I think a rock vibe would force a slightly different melody, because you won't be doing this brilliant strumming pattern.
It sounds quite a lot like the Decemberists I think. The melody, and the vocals are spot on, and the lyrics are wonderful, and vivid.
Great job, really. I really like this as it is!