hey Daagh, quite a collection you have there! I think you have compiled an excellent "strategy guide" so to speak. Especially helpful when vertically scanning answer choices.
For example,
13. Inessential modifiers
The inessential modifiers set off by commas on either sides can be ignored for the most part to facilitate detection of SV agreement, comparisons etc.
These non essential clause modifiers always throw me off... something worth remembering..
Kudos!