User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-3976024-20150901182003/@comment-24834479-20150903173041

1. I don't think that the fruit literally corrupted them, but eating it was a test to see if they were still loyal to God. When Lucifer saw those flaws, he made them fail their test.

2. The leviathans were made before the Earth.

3. I believe it depends on the severity of the Angel's crime.

4. I'm not sure what type of spirit she was. It was kind of like a long term Death Echo.

5. He is the physical manifestation of hunger, and so he looks as if he desperately needs to be "fed".

6. All I know is that a demon can impregnate a woman by possessing her. Perhaps it lays some of its essence within one of her eggs.