benig/gaw, am I reading you correctly in claiming that a woman going sleeveless in the public street is not necessarily assur/pritzus everywhere?! And pray tell where the S”A “doesn’t hold” that displaying the upper legs (i.e. shorts/miniskirt/swimwear) in the public street (or beach/mixed pool) is always assur/pritzus?
Absolutely not. Dressing Derech Pritzus is Assur in all scenarios for both men and women (SA/Rema Yoreh Deah 178.1). The question is whether not covering the knee or elbow is Derech Pritzus. Seemingly shorts or the type would be. The SA where he discusses the issue of Issur for women (Even Haezer 21) only mentions hair.
As they are mentioned in Chazal, ??? and ???? are not subject to minhag. Tzemach Tzedek says regarding this that ???? and ???? are the same letters.
Machlokes Rishonim. The Sefer HaEshkol agrees with you (Pashtus), the Rosh (and perhaps the Rashba) does not. Besides, are you asking about Ervah for Kriyas Shema or a prohibition regarding walking down the street as such? They are not the same.