wow, good luck on those elements. Most I've seen are about 50/50 possibly leaning more toward males and maybe a total of 10 or so.

Murder Most Fowl--cooking competition in a high school setting with a murder.

Thanks for the suggestions so far.  I have read a few of those and will look into the others.

I don't know of a specific script that meets all your specs, but I have directed a fun audience participation murder mystery (The Ghost of Jeb Taylor) by Eileen Moushey

When I was in high school, we did this show called Rehearsal for Murder and set it up as a dinner theater sort-of thing.  It's about a Broadway director whose girlfriend committed suicide, or so the police concluded.  He assembles a cast to stage read a new play--but the play is full of these accusatory scenes pinning the murder on each of them.  It has some fun twists, and, while there's no audience participation per se, it can be interactive.  One character (who's eventually revealed as the killer) stands at the back of the audience for a while, there's a blackout at one point, and one character fires a gun at another as he's running through the audience.  To my recollection, there are about 15 in the cast, probably roughly even male and female, with maybe about half of those good, meaty roles.