yitay: 1) I don’t think that is what he means. I understood his intent that there is something intrinsically and spiritually different about Jews that makes them stand out to those perceptive enough to these things.
2&3) sorry, I didn’t read your question carefully enough to realize you only wanted to answer Tosafos l’Shitaso.
4) it IS Nogea but I was too brief. They continue that people and Karka which are intrinsically not Batel, are Kavua even when not Nikar.