pba: Rabbeim may be suspect because the women come – and the Rebbe’s wife and the fathers of the kids are not there. Different from a wedding where couples are seated together.
Al tarbeh is not a halachah, merely advice – not that it means don’t follow it, but you shouldn’t base a psak on it. And again, does that refer to a conversation with a woman when her husband is away, or is next to her as well?
As for the parsha of arayos on Yom Kippur, I’ve heard many explanations. I heard a pshat from the Maharal’s on it, which say the reason is specifically to show unity in klal Yisrael – that we are forbidden to marry relatives so that we should reach out to others who we don’t know.
I’m not surprised that there are those who want separate seating, and I don’t begrudge them having it. But it bothers me when they say it’s wrong to have it. You want to be machmir? Fine. Don’t impose it on others.