Very good points!
I think you have hit on one of the most important questions within the story, which is, at what point does someone become irredeemable? That is one of the questions Dani is going to struggle with the most going forward.
Indeed, but perhaps Vinicius was wary of who he could trust when it came to raising Dani. After all, even being around such a powerful child and knowing you have influence over them, and thus could use their power to your advantage, can be a source of corruption for some. As far as we know, the only people he was comfortable letting around Dani were other students around his age at the private academy as well as, briefly, some adults like Eric Van Sant.
You're right, we can definitely agree that it was far from a normal upbringing. I think the question now is, did Dani's sheltered upbringing do more harm or good in the long run?