I backspaced an entire post.
TL;DR: We can sort everything out with one simple question. What is this scenario called?
Player: 'I want to do [X].'
DM: 'I knew you would!' *Pulls out notes written a week ago, marked [X].*
Player: 'Wait...How did you know I was going to do that?'
DM: ...Yes.
Define that for me, and a lot of our problems get solved.