Many of these are purely subjective. A 2pt line separator is not more "correct" than a 0.5pt one. Rounded box corners are not more "correct" than square ones. W

Many of these are purely subjective. A 2pt line separator is not more "correct" than a 0.5pt one. Rounded box corners are not more "correct" than square ones. We are just trying to guess the author's own design preference. I did enjoy the parts which were clearly about identifying errors or inconsistencies in design.