Help with Questions to Macbeth : Act II, Scene 4

Act II, Scene 4

1. What additional natural, or “unnatural,” events further the “crime against nature” theme?
2. Who is suspected of having hired the grooms to kill Duncan? Why?
3. Why does Ross say, “Gainst nature still”?
4. Why has Macbeth gone to Scone?
5. How did this honor happen to fall to Macbeth?