I guess I understand. Personally I’m not too worried about Belle. She knows who Captain Hook–his real name and she has an idea of what he wants. She has seen that he can be violent when pushed. So she knows that she is dangerous.
Plus, Rumpelstiltskin will protect her. I get that Captain Hook is dangerous, but Rumpelstiltskin is more so–he has magic and more experience then Captain Hook has. It has been seen pretty easily what he does when he thinks someone is responsible for hurting the people that he loves.