Didn't see the last option but I'd choose that

'mkay. I LOVE Snape, buut... I do NOT think he is well suited for teaching.

The teacher job just doesnt fit him

He's better at being a spy

I think he could've been a good potions teacher because he was super talented at it and knew a lot about the subject, but then he played favorites and was very mean to a lot of his students-

@CHT64 The favoritism was what I was referring to. I think that made me think that he shouldn't have taken up teaching.

Snape was pretty unethical the only good thing was his skills in the subjects.

he was better at the dark arts than he was at defending against it XD