Sounds like an interesting and quite possibly a very rewarding project! Something kids might end up teaching adult something instead....

I think use of disposable camera is a great idea. Not only would it not let you choose shutter speed and aperture, it actually frees you from all the technicality we all get way too involved in from time to time. What you got is a camera and your view of the world - nothing else.

I know there are several types of these available. It might be interesting to let your kids choose color type and B&W type. I know Kodak has a C-41 B&W type. I'd imagine you'll end up getting film scanned at the lab....

I'd actually be interested in seeing your exhibition if you can make it somehow available online.

Is this going to be done in the United States? Maybe if you approach businesses, they can donate you some of those cameras? I bet there are expired ones available....

Good luck to you.