No, the restroom is not shared. You have your own bathroom for each room. 😉
There are shared bedrooms, and yes there's one locker per person in each room. I don't know how big your suitcases are, hence I don't know if they will fit inside. Mine did. I had a big backpack and a carry on suitcase. The lockers are fairly big. If yours don't fit in together you could leave the small one out (for example) under your bed and lock the big one into the locker together with all of your valuables. Just remember to bring your own lock, or else you won't be able to keep your stuff savely locked. From experience I can tell you that the big locks are better than the small ones!
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