Grabs on slopes are tricky since the detection is affected by the altitudes. It is not recommended to use students as bait on stairs.
Major changes to gameplay settings that allow adjustment by the player would have to be in a custom mode which can be added once the game is complete but as of now, there are no plans to adding modes like that.
I am looking into how players use other students as shields but this actually is an easter egg that got popular. The reliability is supposed to be low if you use them as a last resort but if you intentionally try to do this then it might be high. Doing this slows the pred to where you can outrun them, makes them stop from time to time and stuns them if a student escapes. This will have have different effects on different preds.