They make covers that go over your vents to allow you to open your vents while it is raining. From experience, they provide excellent hail protection. I would pull in any slides that you have and not worry too much about your skylight over the shower. If you go up on your roof, you will find that the skylight is fairly flexible. Chances are it will not be affected but if it does break, it is over the shower.
On another note, after a hail storm is a great opportunity to pick up a toad. ON one of our trips in Albuquerque, we were able to pick up a Chevy HHR from Enterprise car rental that had MINOR hail damage. The vehicle had less than 10,000 miles, was less than one year old, and had a sticker price of $24,000+. We got the vehicle for $8,500 out the door and had a base plate installed by an RV shop in town. We sold our Saturn to a dealer and feel that we made a great deal. The auto rental places DO NOT repair their vehicles with hail damage. They get rid of them at deeply discounted prices.