"At least?" LOL, that makes Ben's record of mass murder far worse than Anakin's, in that he knew what he was doing was wrong, he knew from Anakin's example that what Anakin had done was wrong, and - unlike Anakin, whose only parent was dead by the time he turned, with Obi-Wan promptly vanishing - Ben/Kylo actively rejected his parents' pleas for him to turn from the Dark Side, personally killing one of them, leading an attack that nearly killed the other, and attempted to kill his uncle. (Hell, from a certain point of view, he did kill Luke.)
Put it this way: wouldn't you be angrier at someone who decided do drive while moderately drunk (i.e., not too far gone to know better), vs. someone who was so drunk they decided to do so while no more capable of reason than someone who was asleep? I sure as hell would.
So no, until and unless Soderbergh's story pitch leaks, and I'm proven wrong, I have no interest in a story in which Ben Solo earns anything other than a lifetime of humane imprisonment and quiet penance.