Is it permissible for one to limit conversation with his ill-mannered mother to inquiring about her well-being, in order to avoid arguments?

The rights of parents are immense, and showing them dutifulness is among the most obligatory duties, while disobeying them is among the greatest sins. Their right to dutifulness and kindness does not diminish, regardless of their condition or their ill-treatment of their child, for Allah Almighty says: "But if they endeavor to make you associate with Me that of which you have no knowledge, do not obey them but accompany them in [this] world with appropriate kindness." The mother is given precedence in dutifulness, so you must show her dutifulness and obey her in what benefits her and does not harm you. Address her with politeness, reverence, and humility, and do not say to them 'uff' or repel them, and lower to them the wing of humility out out of mercy. You can avoid speaking with her about matters that cause disagreement, and you must be patient, forbearing, and benevolent towards her, seeking Allah's pleasure.