Is it permissible to fish on Saturday?
                                All Perfect Praise be to Allah, The Lord of The Worlds, and may His Peace and Blessings be upon our Prophet Muhammad and upon all of his family and companions. 
It is permissible for Muslims to fish on any day, but the sons of Israel are the ones forbidden to fish on Saturday. Moreover, there is no evidence in Islamic Sharia prohibiting Muslims from fishing on that day. And Allah Knows Best.
                             
                        
                            
                                
                                I have vowed that if Allah gave me what I wanted so bad, I would fast every Monday and Thursday to the rest of my life; unless there is a valid excuse hindering me from doing so. Fortunately, Allah gave me what I wanted, so I started fasting Mondays and Thursdays; however, I stopped out of laziness. What is the Sharia ruling on this?
                                All perfect praise be to Allah the Lord of the Worlds. May Allah`s peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
Allah The Almighty described the righteous people of Jannah where He Said (What means): "They perform (their) vows, and they fear a Day whose evil flies far and wide." [Al-Insan/7]. Accordingly, you must do your best to fulfill your vow. However, if you are unable to do so, then feed a poor person for every missed day of fast (About half a JD), and if you are unable to do that, then offer expiation for breaking a vow, which is feeding ten poor Muslims (About half a JD for each), ask Allah for forgiveness and increase remembrance of Him. And Allah The Almighty Knows Best.
 
                             
                        
                            
                                
                                What is the ruling on a woman shaking hands with the brothers of her husband`s father, and not putting on Islamic wear before them?
                                The aforesaid are strangers to the their brother`s son`s wife, therefore, it is forbidden for her to take off her Islamic wear before them, or to shake hands with them.
                             
                        
                            
                                
                                Should one who doesn`t perform prayer out of laziness make it up later, and how should he/she do so?
                                All perfect praise be to Allah,The Lord of The Worlds                                                                                                                                                              He/she is obliged to make up missed prayers by offering with each obligatory prayer another one, and if he/she offers two, then it is better. And Allah Knows Best.