Is the maternal uncle of one`s mother a Maharam?
                                All perfect praise be to Allah the Lord of The Worlds. May His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
Mother`s maternal uncle is a mahram. And Allah The Almighty Knows Best.
 
* In Islam, a mahram is a member of one's family with whom marriage would be considered haram, concealment purdah, or concealment of the body with hijab, is not obligatory; and with whom, if he is an adult male, she may be escorted during a journey, although an escort may not be obligatory.
                             
                        
                            
                                
                                A pious man proposed to me and my father was hesitant in this regard because he is black, am I sinful if I accepted his proposal?
                                If the suitor is pious, color isn`t a drawback. However, try talking to your father kindly, so that he approves of your marriage with contentment, and that is better for you.
                             
                        
                            
                                
                                Is it permissible for a woman to sit with her brothers-in-law?
                                It is impermissible for a woman to sit with her brothers-in-law, and it is also impermissible for a person to have a Khulwa (seclusion) with his sister-in-law.
                             
                        
                            
                                
                                One day, I swore that my wife will be unlawful to me to quit smoking hookah?
                                All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon Prophet Mohammad and upon all his family and companions.
The best course of action is that you turn to Allah for help and quit the hookah. In addition, acquainting yourself with the risks of smoking hookah will help you take this step. And Allah, The Most Exalted Knows Best