No actual intelligence required, IMO.

This is a trick. What does 'actual intelligence' mean? Term 'intelligence' is already vague, so adding 'actual' creates even more confusion.

  Sentience, to me, goes toward a concept of self. Of being aware that one exists and is responsible for one's own actions.

Responsibility is a social construct. In the past, people would put non-human animals on trial, because in those societies other animals had responsibility for their acts. When it comes to awareness, that's a very vague thing and I'm not sure how you would test it without asking the subject (who might be fooling you). Also, why would having an attribute such as 'awareness' be a reason not to enslave someone who has the attribute?