As someone who has received support and advice from many a member on this board, like the great Gaveston, I can attest that the only reason you've received a vitriolic response is because your musical is a plagiarized mess that no one can take seriously.
I'm a writer, too. I get how hard it is. And how painful it is to hear your work isn't strong. But if you write something [and while I haven't read your libretto, I have listened to your demo] so blatantly plagiarized, you need to be prepared for the fall-out. Putting your work out there means you'll get a wide array of opinions, many of which you don't want.
P.S. Insulting everyone is not a good way to get what you want.
P.P.S There's already a Phantom prequel musical. It's called "Phantom". It's by Maury Yeston. Google is your friend. The End.
"I know now that theatre saved my life." - Susan Stroman