1. Why do you think Bella doesn't want to go to the spring dance? She could easily just have said to anyone, "Let's just go as friends". Why is it that from day one, none of the boys appealed to her?
I think that none of the boys from Forks appear to Bella because she is so much more mature than they are. Mike, Eric, and Tyler are still in a very petty phase, which most young men are at that period of their lives. Bella is uninterested in the superficial aspects of high school... i.e. Dances, dresses, etc. I also believe that her attraction towards Edward has caused her to turn a blind eye towards all the other boys, and she isn't one to settle for less than everything she wants.
2. Bella asks Edward if he has multiple personality disorder because he either seems to be overly friendly or sarcastic moments apart. To what did you attribute Edward's odd behavior?
At this point in the book it was obvious that Edward reciprocated Bella's attraction. He feels that for whatever reason it is unhealthy for their relationship, so to speak, to progress to any other level, so he avoids her all together. At this point, I felt that Edward's more friendly moments were his moments of weakness, when he couldn't deny the attraction.