My sister is looking to get married but I am unsure about who should act as her wali. My father is alive but, he has committed many heinous sins like drinking alcohol, taking drugs, committing adultery etc. He continually slanders my mothers character even though she is a chaste woman I think he should not be allowed to act as wali as by slandering a pure woman, and his testimony would not be accepted in an Islamic sharia court, he has become a faasiq. So can I act as my sister’s wali? My father has committed many transgressions against us, so do we still have to obey and respect him? He still backbites against us and doesn't provide for us, we always lived off the government here, he has never loved us, he always loved his brothers and sisters and their children. He abused my mother and ruined her life. He doesn’t want to fulfill his responsibilities towards us and he chose to leave the house and he hasn't even seen our faces for more than 7 years I understand that he is our father and children have to respect and obey their father but what has ever done for us? He gave away all his money to his brothers and sisters as well as properties and lands. Do we have to respect and obey him as well as keep a relationship with him? My fathers brothers and sisters have also committed many sins, they took the money that belonged to me and my siblings and my mum. These people also supported my father in his wrong doing, his abuse, alcohol, drugs, adultery etc, they slander my mother, accuse her of adultery. my fathers brothers don't even pray, all of these people keep backbiting against us. So do I have to keep contact with these people? One more question, when doing ghusl, I don’t wash my hair with water as I have found that my hair became increasingly dry, greasy and unhealthy from washing it in ghusl. It is genuinely damaging my hair, my hair is okay when I don’t was it with water. Please let me know if my ghusl is valid without washing my hair.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.

The bride’s father is the one who is responsible for conducting her marriage contract and no one else may give her in marriage as long as the father is eligible for this duty as a guardian and as long as he does not prevent her from marrying (a suitable groom). If your father is a Muslim, he is the one who should conduct the marriage contract of his daughter, even if he was a Faasiq (immoral) person, because according to the preponderant opinion, the guardianship of a Faasiq  father over his daughter is valid, as underlined in Fatwa 120675.

You should know that your father has the right for you to be dutiful towards him and treat him kindly and compassionately, regardless of his immorality, impiety and inequitableness. Allaah, The Exalted, commanded children to keep the company of their non-Muslim parents with appropriate kindness even if they order them to disbelieve in Allaah. Please, refer to Fatwa 88120.

Also, it should be noted that you have to maintain good ties and establish good rapport with your relatives, including your paternal uncles and aunts, even if they are immoral and treat you inappropriately; please refer to Fataawa 82279 and 85794.

One of the greatest manifestations of dutifulness towards your father and keeping good relations with your paternal uncles and aunts is to enjoin them to do good, forbid them from doing evil, and help them to return to Allaah in repentance and adhere to the path of obedience to Allaah. However, it should be noted that enjoining your father to do good and forbidding him from evil should be done in a kind and courteous way.

As for your question regarding Ghusl (ritual bath), the Ghusl is valid only if the whole body is washed with water, unless there is a valid and Sharee‘ah-acceptable excuse such as suffering harm if water is applied to the body or parts of it. In fact, what you have mentioned in the question is not a considerable harm. Therefore, you should wash your hair along with all of your body during Ghusl. If washing your hair causes it to become dry, you are advised to consult a specialist to seek treatment for that problem. For more benefit, please refer to Fataawa 82245 and 86534.

Allaah Knows best.