I think that's what the demo showed, a deleted file is put into roamer's trash directory. So when a file is deleted (or moved), the hash points to the new location, the trash in this case.
Do the case studies of these low brain volume patients have criticism regarding the technology and interpretation of the scans? Also have there been studies where such patients have been studied post mortem to confirm the earlier findings?
I would suggest trying a simple game framework such as Löve or pyGame (or pyglet). The former use the lua language and the latter python. I guess Scratch could also be interesting, but I think some 13 year olds may not be attracted by it's "childish" appearance.