Is it permissible for the wife to give the Zakah (obligatory charity) of her money to her poor husband?
                                Yes, it is permissible for the wife to give from the Zakah of her money to her poor husband. And Allah Knows Best.
                             
                        
                            
                                
                                My engagement to a young man was announced and blessed by both our families reciting Al-Fatihah. Is it permissible that I take off my Hijab in his presence?
                                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.
Reciting Al-Fatehah (The opening chapter of the holy Qura'n) to declare an engagement isn`t tantamount to a marriage contract and it isn`t permissible for him to see you without hijab or stay in private with you before the conclusion of the marriage contract. And Allah The Almighty Knows Best.
                             
                        
                            
                                
                                Is washing the private part after urinating (Istinjaa`) a condition, and is it done with water and soap, or with water only?
                                Istinjaa` is obligatory for removing impurity, and it can be done with toilet paper, or a stone, or water. It is preferable to do Istinjaa` first with paper, or stone, or the like, then to wash the private part with water until making sure that the impurity has been removed. Using soap is not a condition, but there is no harm in doing so provided that it is washed off with water. It is also permissible to use either water, or paper if impurity is removed by any.
                             
                        
                            
                                
                                Is it permissible for a man to wear transparent clothing?
                                It is not permissible for a man to wear transparent clothing that reveals his 'Awrah (the area that must be covered). The 'Awrah of a man is "from his navel to his knees", and modesty is more prudent. And Allah Knows Best.