Chareidi KBY Soldier,
I have always understood that Gemara in Kiddushin to be Rav Yehudah testing/teasing Rav Nachman. Rav Yehudah keeps on finding halachic problems with what Rav Nachman is doing and Rav Nachman struggles to answer. But Rav Yehudah doesn’t mean that there is an actual issur, he was just trying to see if Rav Nachman would respond that kol b’isha erva is only about zemer or only niskaven l’hanos or only b’shas kriash shema (according to those Rishonim that understand it that way).
All that being said, the Rashba explains that gemara by saying that responding to a sheilas shalom is worse than regular non-zemer kol. In other words it is just a sheilas sholom by another name.
As evidence that simple talking is not asur even in the times of the gemara, I would present the hundreds of stories in Shas where Tannaim, Amoraim, and regular people talk to the opposite gender without any indication or comment that there was any issur involved.