I think he showed how anyone can view themselves as just doing their job, and he was good at it. I think it is left to us to wonder when he realized that he was an oppressive formce instead of security. He humanized the empire, that they are normal people who think they are truly helping, and it's usually not until they're so far in that they realize what they've been doing.

So is he evil? Depends on whose viewpoint. I bet he thought he was helping, up until close to the end. Andor does a great job at showing us that facism isn't something that happens overnight, it isn't something most people even realize is happening. It's insidious, slow, and you may not know you're even a part of it until your part is done. I think that's the true power of the show.

Remember his question and speech early on in the series (paraphrasing a bit here):

"What do we do here?" General confusion, Dedra quotes from the ISB handbook and is told WRONG

"You want security? Call the Navy, launch a regiment of troopers. We are healthcare providers, we treat sickness. We identify symptoms. We locate germs whether they arise from within or have come from outside. The longer we wait to identify a disorder, the harder it is to treat the disease."

He has no illusions as to what his job is, and is clearly comfortable with the idea of dehumanizing any and all potential dissidents of the empire's order. He is a professional at crushing opposition to a totalitarian regime and knows it, takes pride in it even. Whether he maintains some semblance of workplace comradery or not, whether he thinks Ghorman was a bad idea or not, is a moot point. He even says security is an illusion, that's not his goal, to him some people are simply not people. Merely germs to be cleansed, a disease to be eradicated. So, I would say objectively not a good person.

What could possibly redeem him? He's the Adolf Eichmann of the Empire's genocide in Ghorman.

He hand-waved a planetary genocide by saying “It’s bad luck Ghorman”

Yes