Regarding what you call abandoning the power of choice, here is an example from HPMoR that looks more like a slippery slope.

The point being, said his inner monitor, it's getting worse literally by the minute. The way spies turn people is, they get them to commit a little sin, and then they use the little sin to blackmail them into a bigger sin, and then they use THAT sin to make them do even bigger things and then the blackmailer owns their soul.

Didn't you once think about how the person being blackmailed, if they could foresee the whole path, would just decide to take the punch on the first step, take the hit of exposing that first sin?