Hain tribes in the vicinity of the human arrival have been in contact with them for quite some time now. I think it best not to impose a universal reaction of hain to humans and vice-versa because they were all in tribal groups anyway.

As for the white giants...eeeeeh...

Look, humans don't necessarily have the essence of Toun or Slough in them, but I'd rather not retcon human arrival by having them stomped as soon as they arrived. I've been trying to contrive a reason for them to be considered safe. The best I have is for humans to be so closely related to natural life by coincidence that they effectively have the essence of Slough, but that's a little iffy and relies on Logos' creation method being mysteriously close to Slough's.

I mean, one thing that could happen is for it to be tacit that Logos animated humans with a drop of Slough's rot, like Toun did to assist his creation of the hain.

Does anyone have better suggestions? I'm open to ideas.