1) Voice- the way something is phrased and connotated in a piece of literature. A major part if this comes from figurative language.
2) "Even the baby looks disgusted at how Kentucky is being portrayed- as a hick waste land."
Hick has a negative connotation, and Kentucky being "a hick wasteland" is a hyperbole because it is being exaggerated.
3) A reason you might talk around something is so you can lure someone in to doing something you want. You are trying to make them feel like they genuinely care about you as a person, AS WELL AS whatever they want you to do. It's quite the effective sales maneuver.
4) We use voice because it's something we can't change. However, not changing your voice and letting it shine through gives a kind of flavor to your piece. Something you're to avoid, though, is using personal pronouns because it makes your piece too personal.