Thanks for the question.
1. I started realizing I was attracted to guys as I was going through puberty at 11 or 12. At that time, I didn't even know what it was called and considered myself "normal." So I continued doing what all the other guys did and dated girls. I think some of my ex-girlfriends knew I was gay before I did. By the time I got to college, it was very obvious to me that I was gay, but I kept choosing to date girls.
Finally, I made the decision to start coming out because I felt like I was lying to everyone, including my girlfriend at the time. It was a painful process that alienated some friends and family members for a while. Now, I'm gad I did it. Deceiving the people closest to you and living in fear of being found out is torture. The only thing I "chose" was to be who I was. I don't know why else I would have gone through that process.
2. No, I didn't have any traumatic experiences as a kid. I have an amazing family and I feel I got a better childhood than most people get.
3. This is opening a can of worms, but I don't know if homosexuality is a genetic trait. I just know I didn't get to make the decision to be gay like my straight friends didn't make the decision to be straight. How can two identical twins look slightly different, sound different if they share all the same genetic material? There is probably something more than genetic material (hormones in the womb, maybe?) that is outside our control that determines who we are.
4. Would I change? Thats a really tough question. I feel like it is asking me if I would have rather grown up in CO than on the east coast. The easy answer is, hell yes. But then I think about the friends and experiences I had growing up and I realize I would be a different person. I'm happy and proud of who I am and I'm not sure if that would be the case if you changed my background. But there are many many days when I think it would be a hell of a lot easier to be straight. Actually, then I realize you breeders have to deal with crazy bitches. I'm never going to have to go shoe shopping instead of watching football to make my significant other happy. :)
5. I don't think my environment affected my homosexuality. As I meet other gays, you think I'd start to see a trend, but I don't. It seems to affect people of every background, age, ethnicity, socioeconomic status, religion, political party, you name it. It's actually pretty amazing to go to a pride event and see how amazingly diverse the gay community is. If I have seen a trend, it is this, the more someone chooses to fight it and ignore it, the more damage they've done to themselves.
Hope that answers some of your questions.