Does fasting on behalf of a deceased person permissible?
                                Fasting on belhaf of a deceased person is permissible, since the Prophet (PBUH) said: "Whoever dies while he still has some fasts to make up (of the days of Ramadan), then his heir (any of them) should fast on his behalf." [Agreed upon]. The previous answer is for making up missed obligatory fasts on behalf of the deceased. But if the fasting on behlaf of the deceased was for performing  a voluntary acts of devotion such as fasting....is permissible as adopted by the majority of Muslim scholars and based on the above hadith as they stated "Every good dead intended to be on behalf of the deceased its reward will reach the latter." And Allah Knows Best.  
 
                             
                        
                            
                                
                                Is it permissible for a wife to boycott (not to attend to his different needs) her husband?
                                It isn`t permissible for the woman to boycott her husband unless he is the reason behind that, and it is recommended that both spouses seek the advice of righteous people to make reconciliation.
                             
                        
                            
                                
                                 By slip of the tongue, my son cursed Allah. It is worth pointing that he has concluded his marriage contract recently, but haven`t consummated the marriage. What is the position of Sharia on this? 
                                All perfect praise be to AllahThe Lord of The Worlds and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions. 
This person must return to the fold of Islam by uttering the two testimonies of faith and making repentance to Allah from all acts that lead to disbelief. Also, he must make a new marriage contract because the old one was dissolved after he had committed this act of disbelief. Moreover, since there is no waiting period for his wife, then she is in state of Talaq ba`en baynona Soghra (Minor irrevocable divorce); consequently, she can get back to him only by a new marriage contract. And Allah The Almighty Knows Best. 
                             
                        
                            
                                
                                Is it permissible for us to sever ties of kinship if our blood-relatives` gatherings/meetings involve acts of sin?
                                Observing kinship ties is obligatory, and paying your blood-relatives a visit causing their sinful acts to be hindered , then you should do so. However, if their sinful acts continue while you are at their gathering and they didn't respond positively, then observing kinship ties via telephone and the like will suffice in this case. And Allah Knows