Other than giving Baelfire up to the lost boys, I was under the impression we were supposed to think Hook was a good mentor for him.
I think your first statement answers the overall question, though. At least to an extent. Can you be a good mentor if you sell your ward to the figure you’ll later call a “blood thirsty demon”? That incident isn’t just a accidental miscalculation in judgement; it’s a life altering decision that deeply traumatized and affected the first party and showed the true colors of the second.
On the one hand, I agree that there was a genuine affection between Hook and Bae. “The things we do for our children” speaks volumes to me. He was Bae’s step father in all the ways that matter. But at the same time, I have a hard time saying “he was a good father figure EXCEPT FOR” as if the final outcome (selling Bae) doesn’t totally undermine whatever good mentoring there was in the beginning.