"a crush can never be resolved" Eponine had a crush on Marius, but she could never tell him.
"it seems like every resolution ends in tragedy", well in the novel it happens just that, but I think it specially refers to Eponine's death to save Marius.
"before you go, just these last words for you, I love you so, and love can bring an end to all your woe", Eponine's last wish was that Marius kissed her forehead before she died, and he granted that wish (although he didn't love her).
True, it is from Les Misérables, but the connections don't end there. Apart from "every revolution ends in casualty", that refers to the failed uprising that took place in Paris in 1832, in which most of its protagonists died, there are other references to the novel. if you haven't read the novel yet and plan to do so, come here later, I don't want to spoil anything :)
"a crush can never be resolved" Eponine had a crush on Marius, but she could never tell him.
"it seems like every resolution ends in tragedy", well in the novel it happens just that, but I think it specially refers to Eponine's death to save Marius.
"before you go, just these last words for you, I love you so, and love can bring an end to all your woe", Eponine's last wish was that Marius kissed her forehead before she died, and he granted that wish (although he didn't love her).
I'm not sure if the song is supposed to be sung from Marius to Eponine, or it's just a tribute from Daniel Brummel to her, but one thing I know is I love this song. It made me read Les Misérables, and I loved it too.