I've seen this sort of thing done with torsion-box shelfs, never with
straight 1x stock. It might work, but I would be worried that those
"light objects" might get heavier than 1/4" of wood fibers could
support.

I'd probably sink some inserts into the studs and use short sections of
all-thread to hang the shelves; would be easier to remove when the teen
changes his/her mind.G

Dan