I saw Hunchback in Germany and it was by no means too "dark" for Broadway. There is nothing darker in the show than The Lion King. It's just been the popular excuse because Disney reverted the story back to the original ending of the novel, but if you actually see the show, the only thing too dark was the lighting.
Zimmerman's Candide originated at the Goodman and may be getting a Broadway production so I can see why Goodman is continuing a relationship with her (though I found her Candide to be a bit trite). I think The Jungle Book is far more suited to her talents.
"What can you expect from a bunch of seitan worshippers?" - Reginald Tresilian