Sorry, I didn’t see your first post till now.
“Mai dsani lach lchavrech lo saavid, zehu kol hatorah kula.”
While the pashtus of this certainly seems to imply like you said, I find it difficult to believe this statement was meant to be taken literally. After all, there are plenty of halachos that have nothing to do with menchlichkeit: avodah zora, emunah, etc. These are obviously fundamentals of Yiddishkeit, and yet they have nothing to do anybody but you and Hashem. Therefore, there must be more to the Torah then just bein adom li’chavaro. Remember, there are two luchos, and they are both equally important.