I'd very much like to see this. I love musicals and have acted in 8 differents musicals, or so. Hopefully they'll make it a good one, or atleast make the songs good.
I do, however, understand Anatea's questions. Invisibility can be quite easy to fix, by holes in the ground, etc, etc. Just use your imagination.
And as for the settings: they can easily be changed, using just lights and sounds. For example: Moria. Use black curtains in back, red lights and spots, cavely sounds, maybe some batsounds, fix some bones and you're basically there. Mordor, pretty much the same thing, use mountains in the background, though. Lorien, forest in background, leaves on floor. Rivendell, same background as Lorien, use watersounds. Anduin, watersounds and a long, blue pice of fabric on the floor. yeah, I could go on and on.