Is the questioner obligated to obey his mother in severing ties with his relatives and friends whom the mother considers oppressive or dislikes, knowing that the mother asks to cut ties with a close, committed friend who has not wronged him?

You must advise your mother and gently and kindly prevent her from oppressing and mistreating people and boycotting them unjustly. This is the dutifulness required of you in this situation, based on the hadith: "Support your brother whether he is an oppressor or oppressed," meaning you should restrain him or prevent him from oppression. It is not permissible for you to obey her in shunning and boycotting those whom she has boycotted. Prioritize Allah's command, because it is not permissible to obey a creature in disobedience to the Creator, based on the hadith: "It is not lawful for a man to boycott his brother for more than three nights." It is also advisable to set up an educational program for your mother that keeps her occupied and away from problems, and to recite to her the texts of revelation that encourage good character and kindness to relatives and neighbors. Encourage her to memorize the Quran, increase in the remembrance of Allah, and perform supererogatory prayers. Remind her of the conditions of people in the graves, on the Day of Gathering, and in Paradise and Hellfire.