If being a decent human being is not reason enough to greet everyone with cheerful countenance, nor is the exhortations of our sages, then people should keep in mind that to refrain from doing to is to make antisemites.

Every Jew who is publicly recognizable as a Jew — either by physical appearance (dress, kipah) or even a “Jewish” name — like it or not represents the Jewish people to every non-Jew with whom he or she comes into contact. Likewise, every Torah-observant Jew represents Torah in every interaction with non-observant Jews as well as
non-Jews.

Like it or not, we are all ambassadors, and it in incumbent upon all of us to behave in ways that bring credit to the Torah and the K’lal Yisrael.

I never heard this part of the story before. Are you sure it’s accurate? I’ve always thought this was another gadol story that relates something that a gadol did something we’d find unremarkable from a regular Joe; gedolim hagiographies specialize in these (so-and-so’s grandchildren visited with friends, and he gave candy to the friends too! and the like).