Da….oh where to begin, where do i start…
Separate seating is not a chumra. Rav moshe says any public affair requires a mechitzah mikar hadin, and is doubtful if a wedding is private or public..
Separation of genders was the norm throughout chazal, rishonim, achronim..only in later years did people deviate from it, because of modernity and lack of tznius in general.
Regardless, in Litvishe towns like kelm they had separate sides of the street…the fact that americanized jews didn’t do it doesn’t make a normative standard a chumra.
I will grant that rav moshe calls cholov yisroel in America a chumra, but keeping a normative halacha which had a heter given to it is not a “yeshivish” thing, it’s simply not relying on a heter, Especially when 99% of rav moshes talmidim – excluding notably his sons – held that rav moshe was only giving the heter bedieved, ahen cholov yisroel was hard to come by. Following those poskim – and those who argued with the heter to begin with – can’t be called a yeshivish chumra. It’s rav moshes chidush that it’s mutar.
Tznius – yes, and asheichem yisroel. The chasam sofrr writes that when the surrounding society is lax in an inyan, we are supposed to go to the other extreme to combat it. But most yeshivish people don’t keep all of those chumros…but the poskim are clear, for example, about the 4 inch rule, as well as things rhat are mikar hadin, like slits. Would you rather have chumros in a mitzvah that defines klal yisroel and adds kedushah (ain chiba lifnei hamakom yoser min hatznius..) or would you rather have a culture which teaches girls that it’s a “personal choice” and that they aren’t to be judged if they choose to dress against halacha?
Also, long skirts down to the toes are forbidden in bais yakovs; i don’t know where you get your info from, but it’s probably the coffee room in MO world where only satmar is anti Zionist and yeshiva people are “cavemen”