I have stopped reading after 2nd sentence (as I can hardly imagine how magic of theatre is possible in games), I'm just a big ignoramus, gomene
But.
I think we can get around a lot of these by just dropping the "gameplay" part of it while still using an interactive format.
That's nice
Take away win/lose condition and score, and you are already in the different dimension. What is left in space of no winners and losers? What is to sport if no one competes? Pleasure of experience. A space for a message, plot, characters interaction, narrator, character-player interaction, narrator-player interaction, etc. Imagine an interactive piece where audience do exactly what creator has wanted them to do and it is not a player who decides of the outcome but an author.
I don't really think that it is so difficult. It simply requires different angle.
And once one will achieve this angle space for thinking of the box shall be born. Like a spectacle in which 5 out of 300 audience members are actors indeed and they suddenly begin to interact with the actors on the stage. That's it.