RE: Chalkboard Paint and Glow-in-the-Dark paint
We painted a children's table top with chalkboard paint and it works great. It's was just the kind you get at Home Depot. The table was mine as a child so it took a few coats to get a nice surface but I think a wall would not need as many.
I don't know about a shelf for dust. I would be careful though because my two year old likes to climb on anything he can and I think they would see a small ledge as a step and try to climb on it.
Good Luck,
Michelle I
DS 1 - 7
DS 2 - 5
DD - 1