yes. sexuality is determined entirely at birth.
no. sexuality is decided by life-events and factors out of our control.
sort of. attraction to men, women or both is decided at birth and other kinks are decided later.
no. sexuality is purely a conscious choice.
Everyone is born straight (normal) Little things happen in gay peoples lives that "turned" them gay. Things such as a Boy living with only his mom so he grows up doing girl things because he has no dad to teach him guy stuff or a girl growing up and only having boy toys to play with etc etc