They can help strengthen a point as long as the question is then enforced. They help to convince the listener since usually even thought it's not said we usually think yes in our head after hearing a rhetorical question.
Why would you need someone to do an narrative for you
2, 4, and 5 have to be the answer by process of elimination
Edit: 4 "he followed out his original design," is incorrect but 2 "Endowed with commonsense, as massive and hard as blocks of granite" and 5 "On the score of delicacy, or any scrupulousness which a finer sensibility might have taught him, the Colonel, like most of his breed and generation, was impenetrable." are.