How about in-universe Wikipedia about him? Honestly, Vader is his grandfather
and mentor figure. What we know comes from six movies and a cartoon. He has the entire body of news about him from Galactic Empire (where he was a prominent figure), probably.
Fixed that for you
That is ad hominem, completely untrue and completely pointless. Though seeing that I go quite a bit beyond basic logic into more advanced kinds, I can understand why you may have trouble following (yes I know, Chief, that was uncalled for).
Anyway, "The Force" is not SW universe's substitute for "Magic", it's closer to
its substitute for God. Its treated a lot like one by many, as well. It does have some rules of who can call on it and how (at least presumably), but its sentient and it would appear that by its own will, it can do whatever the heck it wants. Why are you expecting it to follow
human logic? Its nature is unexplained and it works "in mysterious ways", which is what makes it such a powerful narrative tool, while at the same time not a complete game-breaker. It could be likened to an omnipresent Lovecraftian god, a being beyond human understanding, beyond human control, which can be approached, interacted with, but not understood in its entirety. And you are expecting it to conform to your principles of "basic logic" (as in, logic simple enough for
you to understand)? You should also note that "The Force" doesn't even have a morality. It's simply "Use it responsibly and in moderation, you're fine. Abuse it, you go mad". This is the picture we get from the movies. It's been a metaphor for a lot of things (God, magic, political power, just to name a few), but that's the big picture this paints.
It does seem to generally align its will with human interests, but maybe its just not fond of being abused and drives humans it can control to eliminates those who do that? It certainly doesn't seem to want much more than to bring balance to itself, which always involves eliminating darksiders. Of course, by now I fallen in the exact same trap as you did, expecting it to have reactions that follow human logic. So nevermind this paragraph.
What does follow logic are how humans react to it and how they use it. The human philosophy regarding it, human way of living with it. Sensitivity to it seems to be inheritable, but we don't know if the innate Force sense becomes "diluted" with generations, or if it gets stronger in every generation. It might even have a set range of values for each line of force users, with any value in that range being able to manifest in any member of the line. We don't know if it increases or decreases with age (seeing as all the old force users we see trained heavily). We don't know what exactly are the limits of what you can do with particular powers. We don't know if there are limits of what those powers can be, either. There's a reason we don't, and why nobody set those limits (or ever will in a canon book, hopefully). Explaining too much about the fundamental nature of the Force would rob SW universe of much of its mystique. Understanding that is useful when you want to understand the world of Star Wars (and especially if you want to write stories set in it that feature the Force as anything but background).