Some Islamic bookstores sell Qur'an but cut up into 30 booklets each containing 1 juz. Do these count as something you cannot touch when upon impurity ?

A single juzʾ that is bound and sold as a separate booklet still takes the ruling of the muṣḥaf, because a muṣḥaf does not have to be complete, so a person without wuḍūʾ does not touch it directly.