It seems pretty doable to me. Last spring I took Orgo 1, Intro Bio (mostly physiology stuff), and a linguistic anthropology class while doing ~20hr/wk research and running a club. And my school is on the quarter system so all of that was squeezed into 10 weeks. And I didn't find it too overwhelming at all. (Also, that ceramics class sounds cool - I wish I could take a class like that at my school.)