1) Emotions are thrown way out of control in dreams and are far more powerful than normal life.

2) It could have been a false awakening, however on occasions you can hallucinate while awake, happened to me once when I saw an elephant balloon floating around my room. Your dreaming brain is still turned on and your waking mind is turned on so they get overlayed on each other.

3) Normal, when something like that happens do another reality check, one that is fairly reliable. There is a tutorial with common reality checks in the tutorials database.

4) I too think that you are experiencing false awakenings, do a reality check.

5) Plots usually come from movies, books, or TV shows. They are usually multiple things mixed together so sometimes they don't make sense in the least. Imagine a movie that was a combination of The Notebook, Friday the 13th, and Garfield. Your dreaming brain could do it.