Answer:
1. Heathcliff was truly wicked with no good qualities. - Disagree.
Heathcliff's redeeming quality was that he loved Chaterine profoundly. He became resentful because Chaterine rejected him because of his low social-status (he was considered a gypsy).
2. Although Heathcliff is often violent, we still feel sympathy for him. - Agree
While Heathcliff's violence is not justifiable in any way, he did have a difficult life, and that at least makes us feel sympathy for him.
3. Catherine married Edgar for all the right reasons. - Disagree.
Catherine only married Edgar because he had a higher social status and economic means than Heathcliff, but she did not love Edgar, she only loved Heathcliff.
4. Hindley was just a bad person as Heathcliff. - Agree
Hindley resented Heathcliff, and made his life hell. Afterwards, as an adult, Hindely became even more resentful and alcoholic, and left nothing to his family before dying.
5. Ellen Dean was the nicest person in the story. - Agree
Agree, Ellen Dean was simply the housekeeper, and took great care of Catherin while she was ill.