You have a small Hunter like I do. I did not add shelves but instead installed three different Blue Performance bags that have pockets. Most of what I want to store is small and these bags work well.
Even though several of these bags were probably designed to be hung in the cockpit I used 3M Command hooks/tape to hook up my bags. These hook/tape items while designed for homes/apartments/student housing so as not to mess up the walls with holes-- also work well on boats. If you don't like where you hung something you can pull the tab and remove it from the boat without doing any damage.
I have put up a bulletin board on a bulkhead, as mentioned three Blue Performance bags on the inside hull (Cherry wood) and I have two hooks in the head for my PFDs that are on a soft hull covering. All are holding well. I also took down a cleat in the head and replaced it with a Command Hook that was a small ball for hanging my jacket when wet.
In the Blue Performance bags I am stowing extra flashlights, navigation gear, desk gear (pencils, scissors, tape, magnetic pins for bulletin board, etc.), one large pocket for all my charging cords for electronic gear (new category for my boats), boat cards and pads, extra sun glasses and cords and a pocket for my Leatherman tool.
Look for Command Hooks on the web and at your hardware store. I have no connection to the 3M company.