I'm really sorry... But I don't really understand what you're asking here, well, onlye the bare basics, as you only asked the bare basics. could you please specify what you mean with "show" mainly, there are so many ways to intrepertate what you're saying...
Actually I believe there is one on Utopia. I can't remember the res number but move and fly flags are on. Not sure if it's still there as it has been awhile since I saw it. Edit: It even had bench seating for viewers to watch the show.
Yeah, it's player built and takes up a good portion of the res. Next time I'm on I'll see if I can't find it.
Oh yeah nothing official, but there is a player made one. I did find the res it's located on but the player is derelict. So I'm not divulging the location cause I wouldn't want someone wiping it clean.
I think it could. You might not be able to do as much as IRL, but players can walk around, hit at something, sneak (which can be used to convey many different meanings), jump, and move their head around. On top of that, they can speak out in chat. Special effects are also possible: advanced lighting, for example, and spawning and eggifying of passive mobs. Items can be used as well, and can be shown, thrown, and given to another person on stage. Players can set their skin to one made for the play, and heads can be used if one actor needs to play several roles. Oh, and don't forget note blocks and jukeboxes! There are really quite some possibilities.