Ben killed his father to become a Hostile...and he made Locke do the same thing...BUT Locke didnt actually kill his father...
and also...Roger may have redeemed himself before his death....

How did Roger redeem himself? IMO, nothing he could say or do could ever make up for the times (even if it was just that once, when drunk) that he told Ben that Ben killed his mother. That's evil.

Also, I think Ben was already a hostile-in-waiting from the time he ran away. Alpert told him he had to be patient.........probably wait until a number of years had passed, until Ben was old enough to be a productive Hostile (they could hardly take care of a 12 year old).........and old enough to have worked up a good hatred for his father (or for whomever). Seems the hostiles thrive on hate.

IMO, Locke killed Cooper just as much as Sawyer did.........