When my mother got remarried recently, she married a ger (who converted about 40 years ago). They are very happy together! FYI – he does say kaddish for his father per his rabbinic authority. He also goes to visit his mother once a year (she lives far away). My mother goes along and treats her like family too.
I may be wrong, but some of the people shouting about not socializing with non-Jews may have zero practical experience with gerim in their family or non-Jews marrying into their family.
Life is complicated, but that is no reason to get rid of your relatives!! My cousin married a (wonderful and respecetful) non-Jewish man. They were “out of the family” for many years but have since come back. He converted around 40 (orthodox conversion, full Bris) and one of his sons is on the cusp of orthodox and moving closer all the time.
Be careful who you ostracize, as you might turn more people off the derech.