1)  I think that shifting from 1st person to third changes the point of view for the story. Every author has their own style of writing so therefore rules can be broken. Although first person can give the reader a more visual thinking of the story because the reader is allowed inside the characters head and can know what he/she is thinking.

2) Villanueva defines rhetoric as a conscious use of language and a study of humans. A study of the ways in which people have accomplished beyond the instinctual. He says studying rhetoric helps you to study humans.

3) No but if I were too according too Villanueva I would try to mimic the teachers writings. Whatever the teacher would do that's what I would do.