I’m jealous of how much you know about linguistics! Hopefully I’ll study some in the future, it’s so interesting~
I agree with you about the danger of comparing L2 with your native language, especially with Korean being so very different for English, there’s almost no effective comparisons which can be made. I think perhaps the only exception might be loan words like ice cream (아이스크림) and computer (컴퓨터), which often I’ll see in Korean but won’t make the link between until I read the word a few times over.
I’m also a fan of grammar ‘equations’ for language studies, which is probably a reflection of my learning style.