Regarding the bracha of Shehasimcha bimono, the Maharam Yaffa says that since times have changed and now it’s normal for women to be walking in the streets at all times, the Rema which says not to say it in mixed seating no longer applies.
Obviously there were, and still are, big Rabbonim who hold it’s fine. As I said, if you want separate seating at a simcha you are making, go ahead. I don’t begrudge you doing so. But don’t attack those who have mixed seating.