eulerfan, you seem like a nice person. I have gone thru times when I have thought some of the things you are considering.
The "conclusions" which I work with now are that while I do strongly believe in the possibility of reincarnation, I regard that as unknowable. I have no religion or belief in a diety, and am not comfortable with deterministic philosophies.
On the other hand, there are instances when we are approached or meet with a person or situation that almost seems set up by something outside us. I think that our deepest wishes might guide us, even unconsciously to the closest approximation of them, as an act of personal will. I think this view has validity, but is far from complete. (It's important to remember that we function with others who exercise their wills in this world. It is from them that at least some of the external force might be originating.) Sometimes our proximity to them is a dream come true, and sometimes it makes no sense or is a "ho hum" yawning interaction; some exchanges can appear as random acts of kindness or of violence.
It might be as if the universe smiles down one minute and does the opposite the next. I attribute nothing to a universal will, which I don't believe in to begin with. There can be other wills which can be very strong, wills of people, even one person, which can drive others, one by one or by the thousands.
When one is young and "stumbling" thru options which abound, there can be this feeling of discovery of what was meant to be. Yet, it can be, in my view, a stumbling into what one wanted (a positive feeling about the subject, the place, people) without consciously knowing its roots, or even a random occurrence.
When one finds the "right" people or the "right" activities, it can feel like a bonding on the molecular level. It fits. By "right," I mean that which makes one feel alive. I see that feeling of rightness as a mutual fitting of compatible interests and needs. Whether it might be also a reunion of spirits who have known each other in previous lives is open to question. Besides, live for now. I hope you never run out of fulfilling options, for that is a sad place to be.
Keep going.
Cody