With regard to point 3.
I maintained that there are some areas that are “erva b’etzem” and have to be covered regardless of local custom. I will admit that I am not certain that this is right, but I understand the argument.
The Gemara in Brochos (24a) says “tefach b’isha erva.” The Rishonim explain that this means a tefach in the areas that are normally covered. The Gemara asks that you are not allowed to ogle even the finger of an erva. The Gemara answers that it is talking about one’s wife and for krias shma. Rav Chisda says “shok b’isha erva.” Rashi explains “to gaze and so too for his wife for krias shma.” This is strange, didn’t the Gemara just get finished saying that with respect to gazing there is no difference between body parts, why does Rashi explain Rav Chisda as talking about histaklus (gazing)?
L’maysa you can be m’dayek from the statement of “?? ?????? ????? ???? ?? ??? ????? ????? ????? ?????” that there is a separate grade of issur regarding the “makom hatoref.” The Tzlach explains that Rashi understood that if you stare with intent to have hanaah then it is assur even to stare at a finger, however the makom hatoref itself is assur even without intent to have hanaah.
According to Rashi (al pi the Tzlach), Rav Chisda is saying that a man cannot look at a woman’s shok even without intent to have hanaah, because shok is erva b’etzem like the makom hatoref.
The Pri Megadim and the Mishna Berurah pasken like this Tzlach.