I think this is entirely too complicated. The only real advice a young person needs is this: figure out what you love, and then figure out a way to make money doing that.

If what you love is something really general like "helping people", then you have a lot of options. If something you love is really specific like, "looking at insects", then your options are probably more limited. Either way, there's a niche for you that will allow you to enjoy getting up every morning and to feel like you're doing something meaningful.

My personal experience may not be generalizable, but I quit my science-math path in college to become an engineer for the sole reason that my mom and girlfriend battered me into thinking I had to make money. I spent a brief time as an engineer and hated every goddam minute of it. This isn't to say that engineering is bad. A lot of people like it. It is to say that elevating my desire to make money over my desire to love what I do was a bad choice for me. I was able to course correct, and now I have a dream job. The fact that I make ok money is incidental. Even when I was a grad student making $21,000 stipend for 60-80 hours of work/week, I was always happy, motivated, and excited to do the day's work (and I don't mean there haven't been days when it sucked that nothing is going right, that my grant got rejected, that my boss was being a pain in the ass, etc, etc).

One could argue that i've failed into success, but one could also argue that my attitude had a lot to do with that, as well.