I’m private by nature and only share my personal feelings on controversial subjects with those I know and trust.
I really work to find common ground, if possible, with anyone I meet along the way. Sometimes that requires polite silence; however, I will never be silent if someone says truly offensive things about any group whether it relates to their religion, race, sexual orientation or country of origin. To be silent in that case is giving tacit approval or agreeement. No way. However, I don’t debate the point. Just say, “I couldn’t disagree with you more” and then move on.
As for age I have no problem with people knowing I’m 73 but I would never ask anyone else such a personal question. Actually, I think a lot of people put out their age because they are fishing for compliments. My mother in law used to say that people have a special mirror they use just for themselves and the reflection they see is always ten years younger!