Instead of pouting and crying, "Unfair!", it'd be really swell if the OP acknowledged that a good deal of what's been post has been... well, fair. And, honestly, a lot less harsh than what professional critics and producers would have to say (And honestly- don't lash out at the posters here. You have no idea what a lot of us do for careers. A lot of people here are very knowledgeable and are/have been in the business).
Your story may be a prequel to a story in the public domain.
But it is clearly piggybacking off of a musical that is very much copyrighted. The music is at best "inspired" by the music in ALW's musical... at worst, pretty much the same stuff. The problems with what is original have eloquently been pointed out by hyperbole earlier in this thread.
The story itself is problematic.
Yes, I get you are exploring story concepts that are in the original Leroux novel.
However, a large part of what made the character originally so alluring was his mystery. We got a glimpse of his past in the novel, enough to create a mysterious and dangerous figure.
By sucking all of the mystery out of him, we get... a deranged madman who apparently stumbled out of a darker version of A Series of Unfortunate Events.
"...everyone finally shut up, and the audience could enjoy the beginning of the Anatevka Pogram in peace."