I don't think we or science is able to give answers to many of the questions you are asking. At least a 100% affirmative.
As for what age of people you jack off to in your formative years, I doubt it. The kids I know from 12 who are attracted to the more mature end of adults I'm talking over the college age years, were attracted to them at that age of 11-13 or so. They liked 30 and even older women from the start. I liked younger girls from the start. Some of them liked the high school and college aged girls most and that's largely what they have stuck with. Some people's aoa's have moved around or grown, but while I have heard people say their aoa changed completely it's pretty rare.
Also when I was a teenager I almost exclusively looked at and was interested in younger girls. I am also attracted to adults. It did not seem to hinder my attraction of adults.
When I was in college and a little after I was almost exclusively attracted to children. I did like adults a little, but I didn't pay as much attention to them. I fell in love with a then 11 year old girl. As she got older hit puberty and started getting boobs around 13 something weird happened, my attraction to teens started getting far increased. As she got even older and as I started seriously dating adults my attraction to adults above teens seriously increased. My attraction to kids did not decrease. Whether it was because I just never really paid attention to adults enough, whether my aoa was dragged up with the girl I fell in love with getting older, or something else I'm sure we'll never know.
Can you become attracted to adults? Idk. I did and some others did and some did not. It's certainly not something you can force though, I didn't become attracted to adults through sheer will power or something. In the end all I can suggest is that you go out, meet people both male and female, have fun, improve people's lives, don't try to be a victim, and let the chips fall where they may. And if someone says they have the answers 100% to what you are facing treat it with skepticism.