What is the ruling on disobeying one's parents, and what are the limits of obeying them if they command that which does not please Allah and His Messenger? Is this considered to be an act of undutifulness?

A Muslim must not feel superior to others. What you mentioned about your parents and society regarding moral deviation and actions displeasing to Allah are matters far removed from religion. However, you must know that your parents have a right over you that does not cease, even if they are polytheists, as Allah Almighty says: "And We have enjoined upon man [care] for his parents. His mother carried him in weakness upon weakness, and his weaning is in two years. Be grateful to Me and to your parents; to Me is the [final] destination. 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 and follow the way of those who turn back to Me [in repentance]." (Luqman: 14-15). The Prophet, peace and blessings be upon him, warned against disobeying parents, saying: "Shall I not inform you of the gravest of the grave sins?" (He said it three times). We said, "Yes, O Messenger of Allah." He said: "Associating partners with Allah, and disobedience to parents." He was reclining but then sat up and said: "And indeed, false speech and false testimony." Therefore, it is obligatory for you to honor your parents, respect them, and accompany them with kindness, but do not obey them if they command you to do something that does not please Allah.