I'm currently more swamped with school stuff than I had anticipated. I have to read three books (two French, one English), prepare a presentation on The Simpsons for English, and I'm learning Japanese and currently memorizing two of the three alphabets. I'll have the translated map ready for you as soon as possible though.
For now, I'll just put up the translations I've already figured out, without an edited map:
Hinterbühne = Backstage, where we're trying to get.
Bühne = Stage, of course.
Kulissen = Scenery. Houses, trees etc. painted on cardboard and stuff.
Geräte = Not sure what exactly this is, but I guess it's kind of a janitor's closet or something.
Geräte-Ablage = The same, I guess.
Chorprobesaal = Where the choir has their rehearsals.
Bühnentreppe = The stairs leading to the stage.
Ankleide-Zimmer für Solo-Herren = Where the male solists get dressed.
Ankleide-Zimmer für Solo-Damen = Wait for it... Where the female solists get dressed!
Vorz. = Vorzimmer = Where you wait to be let in.
Kaiserloge = Emperor's box, literally. Basically, where the head honcho sits. Or possibly monsiuer le cardinal in our case.
Zuschauerraum = Where the rest sit
I can't exactly make out what it says in the box on the right, but I guess it's Intendanten-Loge = Intendant's box. Id est, the guy who runs the theater.
Umgang = Tower gallery (?). From where you get to the seats.
Terrasse = Terrace. So... yeah.
The tiny rooms with "Damen" and "Herren" on both sides are probably toilets.
Eingangshalle = Entrance hall.
Vorhalle = Lobby
Kasse = Cash desk. Money or you no get in.
Chorherren = Literally, choir men. No idea what this is supposed to be.
Chordamen = See above.
Kapell-Mstr. = Prolly Kapell-Meister. I guess that's some conductor's office or something.
Wartez. = wartezimmer = Waiting room.
Sekr. = Sekretariat = Secretariat
Kalkulator = Accountant? Dunno, first time I've seen the word other than as a really old word for calculator. >_>
Amtszimmer d. Intendt. = Amtszimmer des Intendanten = Intendant's office.
Erfrischungen = Refreshments. Prolly where you go stock up on coke and popcorn.
Herren/Damen = Probably toilets again.
Halle = Hall. Ain't I smart?
Ablage = See Geräte/Geräte-Ablage
A bunch of stuff I already covered.
Wirtschaft = Once again, no idea what it is. It might be something like a dining hall or sth like that, but don't take my word for it. Leo.org says economy (most likely not), inn or management.
Schenke = And old word for bar/tavern.
Festsaal = Ballroom/festival room.
Orchester = Orchestra.
Damen/Herrenz. = Damen/Herrenzimmer = Once again, probably toilets.
Überdeckte Halle = Covered Hall.
Terrasse = Terrace, again.
Konzertgarten = Concert garden literally. My guess: Where people go out to have some fresh air between compositions?
Ankleideraum = Dressing room.
Hinterbühne = Backstage once more.
Altar darunter Maschinenhaus = Altar, below it ... um, machine storage or something.
Orchester bez. Vorderbühne = Orchestra/stage.
Kleider-Gelaß = I've never heard the word Gelaß, but I assume it's checkroom or something.
Kasse = See Kasse, above.
Vorraum = See above.