I like this idea, but I think the "step" shelves need some more support. Garage shelving idea: the lower shelves actually glide out so you can step to reach top shelved items. Then they slide back to the wall.
Bunks in the closet, leaves the rest of the room as a play area. This is a GREAT idea! I would take the doors off though. Maybe cute curtains instead. I used to love hanging out in my closet. And to free up the room for more play area?