I thought i was so smart when I saw "thus" lol

Is this necessary for Logic reasoning? Im a visual learner (hence why I opted for 7sage instead of LSAT demon) and reading all these for nothing, can someone tell me to what extend this lesson is relevant towards LR and RC?

Thank god for this lawgic language cuz the circles were freaking me out lol

I got a bit confused on the commentary one because why is the subject not "Elbert's commentary" and just "commentary"? Like I know its Elbert is a modifier but it was his commentary... sorry this is a bit confusing