Allah The Almighty Made marrying up to four women lawful, but human beings prohibit that with their own land laws. What is the position of Sharia on this?
                                All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
What Allah has made lawful, human beings can`t make it unlawful. However, taking the decision to marry up to four women requires material and physical abilities, in addition to having the courage to make such a decision. And Allah The Almighty Knows Best.
                             
                        
                            
                                
                                Is it permissible for the man to go out wearing shorts?
                                All Perfect Praise is due to Allah, The Lord of The Worlds
It is permissible so long as his Awrah (private part), which is between his navel and knee, is covered. However, the regular wear traditions and modesty are to be observed. And Allah Knows Best
                             
                        
                            
                                
                                In our region in southern Oman, specifically in the city of Taqah, there is a mosque that they say was built hundreds of years ago. This mosque is surrounded by graves, meaning it is in the middle and the graves are around it. People in our area differ, with some considering it permissible and others considering it forbidden to pray there. Moreover, my grandmother saw in a dream that she entered this mosque..."
 
                                Praying in this mosque is valid and and there is reprehensibility in its location so long as no grave exist within it. Besides, Sharia rulings aren't derived out of dreams. And Allah Knows Best. 
                             
                        
                            
                                
                                I suffer from absentmindedness and constant worries during prayer, what should I do?
                                You should take refuge in Allah from the whispers of the devil and life worries. You should also seek Allah`s help and offer a lot of Istigfar (seeking the forgiveness of Allah). And Allah Knows Best.