You should combine the studying in your drawings. For instance, if you need to remember that Abraham Lincoln was born on February 12, 1809, then write that down and doodle something for it. But you have to time yourself. Give yourself a maximum of 20 seconds to get the idea down. I actually take notes in Photoshop with my tablet during my computer class.
Maybe associating specific pictures with facts would help you remember more things too? It's just a theory. But this may be a way to save time on studying, or just making it more fun. And who knows - maybe you'll get inspiration for your digital art from your school assignments.
Well, I love learning new stuff I didn't know. But I don't really like Studying either. Every time I open my books, I probably end up drawing in that book with my pen (or sometimes Pencils). To put it simply, I easily get distracted. So my answer would be no....
I got caught all the time, but I kept my grades up and I was friends with most the teachers so when they "caught" me they would usually just comment on how good my pictures were. Just keep your grades up and be friendly with the teachers, you will be all right!