Is it permissible for a woman to seek Khul' from her husband who abuses her, given that she was forced to marry him, and would it be considered disobedience to the father if he severs ties with her because of it?

A husband's harshness, ill-manners, and striking of his wife are ظلم (injustice), and not characteristic of the best of people. The wife has the right to seek divorce due to harm. If he does not respond, she should escalate the matter to Islamic centers. It is not permissible to resort to man-made courts except out of necessity. The father erred by forcing his daughter to marry someone she did not desire and by compelling her to stay with a husband who harms her. She is not obligated to obey him in this matter, as it is not an act of kindness (ma'ruf), and he has no right to disown her or deprive her of inheritance.