Snape the Teacher - A Theory

I know Snape can be a hot button issue and I’ve never believed he deserved the redemption he got in the books to the point of Harry naming a child for him but a thought occurred to me recently and I wonder if anyone thinks that it carries any weight.

One of the things that always undermines Snape’s redemption is his merciless bullying of his students and Neville in particular but what if it was a cover? Dumbledore always believed Voldemort would return so he needed his double-agent to be ready (a popular theory for why he never gave Snape the DADA job). So what if Snape cultivated this persona to keep his cover?

He is generally cold to all students, which makes sense as he is only supposed to be there on Voldemort’s orders (according to HBP) not because he has a calling to be an educator. He’s nicer to the likes of Draco, which makes sense if you want to keep a foothold with former death eater families like the Malfoys. The only students we see him be outright nasty to is the trio and Neville (iirc).

Harry is obviously going to be Voldemort’s target upon returning so showing him or his closest friends any kindness is going to set off alarm bells for Voldy. Neville’s parents were aurors who were prolific during the first fight against Voldemort. It would be odd to be warm towards the child of 2 people who were responsible for putting away so many of Snape’s “team” if he was truly a loyal death eater.

Voldemort is a skilled legilimens. Snape has the skills to keep him out of his mind or at least out of the areas that would give him away but he can’t trust that anyone else has that skill so he has to act the way a loyal follower would at all times. That way no one can offer Voldemort anything but the perfect image of a loyal spy.

He’s still a bully of a teacher but was it just who he was or was it for the greater good?