I'd like to be okay with getting the Bound Sword tome and Bound Bow tome early. Reaching that point for Bound sword is easy. Your character heard of the man that wishes to retake his home outside of Riften during their travels. It's the reason you crossed the border in the first place. This allows you to start Infiltration without feeling bad.
Is there any type of logical reasoning for going after the Bound Bow tome inside the prison of Fort Amol? If not, it just feels wrong.