i can see multiple explanations for cannon dumbledor cold manipulative bastard kindly eccentric old man other things
Rowling intended Dumbledore to be the all-knowing all-powerful wizard, who truly had everyone’s best interests at heart. However, she apparently had no real knowledge of psychology, or she would have researched his character more fully. I have seen him portrayed as many things, like you said, from kindly but misguided, to evil incarnate. Personally, I refer him to…as Lilo said to Stitch, “have a medium high level of badness.” This is, by no means, the worst I’ve written him.