Michael, I suggest you look at other dying forms for guidance on how to make a living as a playwright. Opera has been dead for over 50 years, so creaters of "new music theater" have been experimenting with new business models - one's that have nothing to do with the traditional roles of composer/librettist submitting work to artistic director/opera company in the hopes of workshop/production. Granted, theater has a longer tradition of devotion to contemporary work, but so many works are, like new music theater, being developed in collectives, now, and I am amazed that you, this late in the game, would still seek that brass ring of "legitimate theater" validation. So, the point is not so much to self-produce, as to collaborate with others, to form a company in which the hat of "playwright" is not so explicitly defined. If you give up that dream and that ego, you may get more chances to play in the theatre, and see your plays become reality.
Barry Drogin