Is God omnibenevolent?

Yes. God loves you. God always has loved you and always will love you. No matter what you do, God will still love you.

That doesn't mean you can't hurt God, or disappoint God, or hurt and disappoint other people, or bring punishment on yourself. God can hate and revile you as well as love you. If you torture and rape your mother, will she still love you? Maybe, but as much as there is no limit to her love for you, there is no limit to the depth with which you can possibly betray and harm her and the relationship.

Since God is not yet omnipotent, there still can be permanent harm.