I'm exceptionally nice to people who seem like school shooter material to survive the shooting if they ever snap
Really? Why are you nice to potential school shooters?
That kind of people gets more hatred and they will be more likely to hurt me. Better be nice to them and hope they don't snap.
You shouldn't be nice to people just because you don't want to be harmed. If you think someone is violent and has the potential to create violence you should report them.
I don't want to cause any trouble and I don't want to be a victim of a school shooting.
I understand your concern, but it is highly unlikely that you will be the victim of a school shooting. Your plan doesn't guarantee your immunity anyway. Don't be nice to people just to get something in return.