I'm still figuring things out for myself, so it's bound to be a bit confusing :D Hopefully more intriguing than confusing though.
Is there magic? Yes, but maybe not so much as people believe. Is there a curse? Kat certainly believes so. How does the curse work? I'll have to get back to you on that :D I'm only certain that she can't deliberately say something like 'In two minutes it will rain' and have it happen. Magic's tricky like that.

I think Confessor is a good way to think about it, because while Kat is held in great reverence for her position and real or presumed talents, she's also feared and hated by many for the same reasons - along with gender issues that she's a High Queen and not a King, and that she's preparing them for a prophesied[?] war.

I don't think Sky is really human, but Kat loves him as much as a person - as a pet is a family member - and it is her perception that counts, so they're erring on the side of caution here.