tzippi
I’m not sure what you mean by “I always thought huh was the definitive answer: why not exercise our muscles, at the very least.”
I’m assuming you don’t mean that we are free to maintain shitos in contradiction to the gedolim. but then i’m not sure what you do mean.
re: Avos 3:14 chaviv adam shenivra btzelem…
you skipped out 2/3 of the mishnah:
chavivin yisrael shenikri’u banim l’makom…
chavivin yisrael shenitan lahem kli chemdah…
clearly the mishnah is differentiating between jews and goyim and putting us on a higher level. and if that doesn’t convince you, ask your husband or father summarize sha’ar alef in nefesh hachaim or yesod vshoresh ha’avodah and see how they go on and on about the chochos that we jews have in this world beyond any other being that even the rishonim argue whether malachim are greater than us or not.
Certainly we should all strive to be kind to all goyim both because of yashrus and to not be mechalel shem shamayim, but we can easily understand how someone who goes around knowing that he is a ben Melech higher than even the malachey shamayim can have trouble in this area.