Half baths are generally useful for guests and for use by families with more members than bathrooms. If your situation is neither, the transformation into a closet makes more sense. Having liven ib homes with minimal closet space---and building a house with extra closet space(and filling those)---the closet space was much more useful.

However, to properly convert and at the same time make it possible for a future owner to convert back, three things need to be done. The three water feed lines need to be permanently capped(soldering caps on the lines) to prevent future leaking. Reusing those lines is a matter of cutting off the caps and installing new lines/shutoff valves. If the lines are left above/out of the floor/wall, a cover needs to be fabricated to protect the ends. The toilet waste line needs to be plugged and covered. Third, leave a note on a wall with the information about the conversion so a future owner can be aware.

Any suggestions on how/where I could put a small bar for hanging items? On the sloped ceiling?

Another photo would help so we can see the ceiling.

Adding a shower to that would increase the value to your home. Removing it will decrease the value of your home.

Just ignore the fact that it’s a half bath and put some hanging rods in if you need for storage outweighs the ability to have two thrones occupied at once. If you’ve never had the whole family down with food poisoning, you may be underestimating how handy even a half bath can be.

Leave the half bath because it's a huge positive for most people.

Convert it to storage. My parents never used the tub in their full bath and so used it for storage with a rod across the top and additional stuff in the bottom.