If you haven't already, get some graph paper. Measure the size of your space including window, door, and the space the shelves take up. Then figure out the size of your sewing table, etc and how this will fit into the allotted area.
Yes to the over the door clear plastic shoe bag...I just picked one up at W.mart for around $8.
Hanging a design wall (back side of a vinyl tablecloth) over the shelves sounds like a great idea.
Can you attach S hooks to the wire shelves? I was able to do this and then hang wire baskets to the hooks on the exposed end of some shelves in a WIC. You may be able to make fabric baskets instead of buying "new". Maybe some ideas here...you can customize size to your space.
https://www.patchworkposse.com/50-fa...ins-tutorials/
Best of luck as you design this little cozy space.