1.) The neighborhood represents conformity because everyone has is pretty equal and has the same lifestyle. They all have decent sized houses and cars. The men all go off to work in the morning while the women stay home to cook and clean (and gossip).
2.) No he's not voluntarily a non-conformist. He was created by the inventor and he's unfinished because the inventor died before he could give him real hands. So he hides away up in the mansion until the Avon lady comes and gets him. He
wants to be a conformist because he's in love with Kim, the Avon lady's daughter, and wants to have a normal relationship with her. But, he can't because A) she has a boyfriend and B) her boyfriend doesn't like Edward. Also, Edward is really naive and has missed out on any kind of socialization. He tries to become a conformist by learning the social norms of the community, but his innocence gets him into trouble (there's this part when this slutty lady in the community tries to basically rape Edward and he gets scared and runs away. After he rejects her, she's embarrassed so she turns on him and starts spreading rumors about him and treating him badly).
3.) Edward has to struggle with learning well-established social norms. That's why he enjoys hanging out with Kim's brother, Kevin. Edward is able to relate to children more than adults (because he's still learning). Edward's non-conformity isn't initially problematic for the community because they seem to take him in with open arms. But after Kim's jealous boyfriend (I think his name is Jim?) interferes and gets Edward in trouble (Jim gets Edward to break into his [Jim's] parents house but Edward gets caught and gets sent to jail), the community starts to shun Edward and they no longer view his hands as tools of service, but tools of rebellion and even violence.
4.) It depends on the person. Sure, the person will feel fulfilled in the sense that they are being true to themselves. But by being a non-conformist, they risk being shunned by their communities and even families. This may leave the individual feeling lonely and unfulfilled. If someone can be satisfied with no one elses opinion except their own, then yes. If they need the approval of others to be satisfied, then no.
5.) I don't think it was realistic at all. The community saw this scary looking man with scissors for hands and welcomed him like it was no big thing. If that had happened in any realistic community, everyone would want to stay away from him. I think Burton wanted the audience to feel sympathetic towards Edward. If the community had automatically shunned Edward, he would have gone back up to the mansion and that would have been the end. By accepting him, they allowed time to show how naive he is and how he is so trusting of people. Burton wanted to show how Edward is innocent and easily manipulated and that the community (mostly Kevin and the slutty lady) tainted his innocence.
Anyway, I hope this helps. =]