Yeah, he'd still get merit points for turning in his homework and doing well in tests, he'd just be missing out on the points he'd otherwise get for attendance! But if he does really well in class anyways, the points sort of balance out as compared to an average student with perfect attendance.

He will absolutely get a talking to /: Submissions are to the student council who will turn it down, but later one of the second year members will take Natsume aside and ask what his price is for the homemade bomb.