People don't decide to become gay, they're born like that.
Yes -- if they have heterosexual intercourse. And a lot of gay people have had at least one heterosexual experience.
Nobody becomes gay. People are either born gay or they are not.
Gay women can get pregnant. To be pregnant you need the egg and the sperm, so homosexual sex won't do the trick. But if a lesbian has heterosexual intercourse or artificial insemination, or a gay man had sex with a woman (straight or lesbian), pregnancy could occur.
The only way to get pregnant is if you are a female - with eggs, periods, and a womb. If you're a lesbian and have sex with a man without using protection then you will most likely become pregnant. Gay men cannot become pregnant, but they can impregnate women. If you are a lesbian woman, you can get pregnant, but only if you have sex with a man or undergo a fertility procedure that uses banked sperm cells.
No, there is no study that supports this.
No, most people don't want to be gay. People who are gay are either happy, or not, with the way they are. People who are straight do not want to become gay. Anyway, it is not possible to seriously change from one to the other. Nobody can become gay, everyone is born knowing they are gay. Some people are too afraid to come out and accept that they're attracted to their gender, so those who "become gay" have always been gay, they just came out a little later than they should have.
Gay people do not "become" gay. Sexual orientation is fixed at a very early age, possibly birth or prenatally. There have been gay people since the dawn of humanity.
You're thinking of transgender people, not gay people. Gay people do not "become a girl" unless they are also transgender. Transgender people can be gay, straight, or anything else.For more information about the hormones that Transgender women take, click here.
All people, gay or straight, adapt to their environments. But if you are asking if a gay person can become straight, the answer is no. It's not possible.
Most gay people are already normal. Just as most straight people are normal.
People don't "become" gay. It seems to have something to do with fetal development and genetics. In any case, sexual orientation is determined by age six. Many people experiment with a same-sex relationship without actually being gay, and some people are actually bisexual. In the long run, however, you are what you are.