@madargon There's a UI affordance that I sadly haven't seen outside of games: instead of asking people N times "are you sure" (with N varying depending on the severity of an action), have the button that triggers the action require being held down and have it visually represent how long you still need to hold it (e.g. by making it a progress bar, too). Then you can vary the time based on "severity" of the action.

I think that is strictly better, because it gives the user an intuitively clear feeling of how serious this action is (similar to the pistolgrip handles used to control control rod movement in US naval reactors requiring larger force to turn in the "outward" direction than the "inward" direction).