“Every minute a chabadnik asks a goy “excuse me are you Jewish”, he is fulfilling a mitzva of ahavas yisroel and is pikuach nefesh”
Ummm, what? Did you mean to say “asks a Jew who otherwise appears to be a goy?”
If not, I fail to see how asking random goyim if they’re Jewish has anything to do with ahavas yisrael.