i also had the same thought about ikana being a sort of opera area. it has that wide-open feel to it, and i think the tracks would lend themselves nicely to that sort of vocals.
a question. in the final act, when all hell's breaking loose over termina, does that mean that each style of music (rock, opera, orchestral, etc) will be competing? that could lend a great deal of chaos to the experience.
also, my 13-year-old sister might be up to playing pamela, romani, or one of the younger roles, though i have yet to ask her. i'll letcha know