Avram MD, I think you wrote a beautiful and well-thought-out post. I happen to believe that sof kol sof, the Tanna was NOT of the mindset that you would like to attribute to him, because he lived in a time when men and women had relatively little to do with each other in a social context. Possibly, some women went to sell or buy in the market place, but there was not so much interaction. That really held true for many societies. I think the Tanna simply did not believe women and men should have much contact. And many people issued their opinions because they had miserable marriages (the takanah of Rabbeinu Gershom re: marriage to no more than one wife at a time, comes to mind).
I do not mean to sound disrespectful in any way either to our holy Tannaim, to the Mishneh, or to hashkafos of people of yesteryear. Neither do I want to be disrespected myself for wanting to make a clear distinction between the actual halacha and (even heiligeh) people’s personal viewpoints that may be heavily biased because of cultural influences of their time period.
I once asked a shailah of a Rov on behalf of some women who did not carefully remove their nail polish before going to the Mikveh. His response to me was not the p’sak kosher or posul tevilah, but rather, “There is absolutely no reason why women need to wear nail polish!” Whether he is right to feel that way or not, that was not the shailah I asked him, and it is irrelevant to halacha l’maiseh.