The gameplay loop you outlined is certainly a classic!
My input to avoid scope creep is (perhaps unfortunately) to just go ahead and test things out. As much as I think your theory is really solid and I resonate with many of the things you talk about, even the best designer in the world will fail to account for something.
That said, items which focus on making a measurable impact on gameplay are some of my favorite in any game, so I'm excited to see where you take them!