I get what you mean but at the same time you evidenced the very thing I'm struggling to comprehend.
If anyone has clear insight into how Alexander became the man we are told it would be her, no? We know part of the reason was the torment he suffered at the hands of his sisters, correct? Callista leaving and Cole's betrayal only exacerbated this, right? Then why oh why would Callista raise Kane to be good and righteous but leave him in the dark and deliver him to be tormented by the Karlsson's?!?!? Doesn't this seem counterproductive? Doesn't this almost ensure he becomes evil, sadistic and antagonistic towards her? What is her reasoning here?
It pisses me off to no end that she did that to her own flesh and blood. And to poor Seth. But Olivia, who isn't even her daughter, she protected and trained. Olivia, she armed with knowledge and a plan. Olivia who would not be in any semblance of danger simply by being the daughter of who she is, she coddled and prepared. It's ludicrous.
I stand by my opinion. She is at the very least as bad as Alexander. Different kinds of evil perhaps, but similarly evil nonetheless.
I think Alexander and his Sisters had a very good relationship, they also adored Callista and left together with her (correct me if I am wrong). I think you meet one them in a Olivia flashback.
Alexanders downfall began already when Callista was still there (hence the cheating with Elena), but afterwards intensified extremly, since he lost the only thing that acutally had a meaning to him (Callista, his sisters and Cole).
Why he initially began changing is not completly known, but I assume he simply got corrupted by power, after he fought himself up from being not much more than a slave and then becoming really powerful.
I always assumed that Alexander hoped for Kane to be like him, but maybe a better person, that is why he says in the intro that it
could actually be a good change. Then there is the sentence about power in the hand of one persons always leads to cruelty, I assume he maybe hinted there, that the power should not fall to Kane or the winning sister alone, but instead to a team of the two or maybe even three (like in two sisters at the same time

- Tess said there is an ending with good Olvia, good Kane and Veronica being a triplet, but they all need to be on a similiar power level).
About Callista, I agree with you unless at lest one of certain things are revealed to us: First, if she was actually under absolut
extreme surveillance (and I mean super duper extreme, permanent complete video and audio surveillance without a chance to block it, even for minutes) and it was impossible for her to give him hints/prepare him. Second, she basically has an absolut fail proof super plan to get him out of there (which is most likely not the case, since it is possible for Kane to die in the game show, so not really fail proof). Or third, Kane actually is informed about a lot of things and only fakes he doesn't know, just like Olivia (this is unlikely since he
can fail so hard in the programm

).
We don't know what exactly she taught Kane, just that he had to learn a lot and from his genetics that he actually should be some kind of genius, like the rest of his family. So yeah we have to wait until more is revealed, but right now I agree with you, Callista is an absolut shitty parent from what we know so far. I hope how Kane handles her is not necessarly bound to him being good or evil, but an actual player decision.
Would also be much better for you if you knew what you were on about.
They are not blood related, but a lot of people would consider adoptive siblings (especially when raised alongside each other and not even knowing it), as siblings too. So no genetical incest, but definetly emotional incest (the closest we get to genetic incest, is with Delilah, who is Kane's cousin, but the stance on cousins is ähh controversial

).