Your beardie is lucky to have a human slave who loves him so much.
It's good that he likes the calcium supplements, but hopefully you can get him to eat bugs and/or some greens along with it -- everything in moderation. He may be craving calcium because he needs it, but he needs a balanced diet too.
The nice thing about pooping in his bath is it makes it really easy to clean up after him -- all you have to do is dump it down the drain. Our beardie was "housebroken" that way when we first got him. As long as you are able to give him regular baths, I'd encourage that if I were you.
As for school, the only problem I see with that is if you end up getting lousy grades because you're thinking about your beardie all the time... :wink: