I like the little day bed and the window and beat board walls. day bed on plywood base with built in table. we would put the long edge further back for under the bed storage space. I also would want to paint it like white or something.
We've used a similar corner shelving unit to create space in a small 7 by 9 ft room. It's a great, easy shelving solution for small spaces (although installing it was a bit tricky as the walls weren't plumb.