There is a school of interpretation that sees the biblical story of Joseph as a symbolic precursor of (or perhaps herald for) the coming of Jesus. (Needless to say, this isn’t part of Jewish interpretation and, IMHO, it takes a huge amount of stretching to get there.)
However, some of the folks putting on the play … Technicolor Dreamcoat seem to use that, and arguably Rice/Weber had that in mind. So, yes, the song is mystic, if it’s anything. Given that ALW had a hand in it, of course, it could just be whatever words fit to make rhymes, so long as each little phrase sounds like it has meaning.
“Drew back the curtain” would imply pulling away the curtain of reality to see the deeper meanings beneath
Eyes are closed to see better – that’s part of the dream-interpretation thing, that divine messages are clearer visions that simple eyesight.
“Someone is weeping” is presumably Jesus, weeping for the world.
“The world is sleeping” means they don’t see Jesus for who he is… well, OK, for who the songwriters think He Is.
(( Parenthentical aside: a Jewish interpretation of this would be even more stretched, but there is a psalm about Rachel – Joseph’s mother – weeping for her children, the Israelites, in exile. ))
The second verse you’ve cited is, I think, is just a way of saying “The play’s over.” Return to the beginning means he’s back with his father and brothers; the dream (his story, the play) is now ending so the stage lights are dimming, the world is still waiting for the Messianic Era.
I’ve always hated (with a passion) the line “Any dream will do.” Presumably, the sentiment is “Follow your dream, whatever it is.” Sorry, I don’t agree. I don’t think that a dream of white supremacy and the good old days of subjugation of the blacks “will do.” I don’t think that the dreams of Islamic terrorists “will do.” I think the notion of “Follow your dream, whatever it is” is dangereous and leads to madness.
Anyhow, that’s my interpretation, whatever it’s worth.