I'm 27 here.
1. I simply define diversity as variety.
2. Around here (Chicago area) pretty good, though there are some areas that tend to be dominated by specific cultures.
3. At the very least, I learn about others ways of life. I enjoy Art from many different cultures as well. Most specificly, I love cuisine from all around the world, and there is a wealth of diversity when it comes to food here. I also very much enjoy movies from all over the world. Perhaps films don't relate to diversity as a local trend, but instead, at a global scale, but it's interesting to see the similarities as well as the differences between foreign cinema and that of the USA. Also, Music. I tend to listen mostly to metal and rock, and there are excellent bands from all over the world. Music is a universal language.
4. Things are more interesting. There is a lot of spice to life.
5. Unfortunately stereotypes and/or historical feuds tend to follow diversity. This results in tension and people doing things that they probably should not be doing.
6. People need not be afraid to experience things in life.
7. Locally, Everywhere I go, from the workplace to restaurants to movie theaters to my own neighborhood and town. On a larger scale, the east and west coast of the USA seem to have the right idea from what I've seen.
8. Everywhere
9. I don't know. I try to keep an open mind and tolerate others regardless of our differences. Lots of other people that I know seem to do the same. Perhaps just education is all that's needed.
10. As a matter of foreign policy on a global scale, it's crucial. Ethnocentrism in small doses can give you a sense of pride and even patriotism, but on a larger scale, it does much harm and creates conflict.
11. More diverse than some, less than others probably.
12. I think much more History from many more cultures should be taught in schools. Currently, most middle and high schools tend to focus strictly on European History and American History. There is MUCH to learn about African and Asian history as well. "Diversity" as a concept, shouldn't need to be taught, because exposure to history should set a good foundation.
13. I don't know. From my own limited experience in the Chicago area, things are already pretty diverse.
14. Try to make less rash judgments. Realize my own ignorance whenever I can.
15. This is widely open to interpretation, but at the very least I would say some level of appreciation and acceptance for things that they may not be "used to." At the very least, an open mind.
Just my two bits...