Could You (Grand Mufti) explain why the Prophet (PBUH) refused to grant Ali, who is already married to Fatima, permission for second marriage?

What is the basis on which the two following seemingly contradictory Hadiths were combined: First, "The boy is for (the owner of) the bed and the stone is for the person who commits illegal sexual intercourse."{Related by Bukhari & Muslim}. Second, " Any woman who brings to her family one who does not belong to it has nothing to do with Allah (i.e. expects no mercy from Allah), and Allah will not bring her into His Paradise."{Related by Abu Dawud}.

Is the following Hadith graded as Sahih(authentic): "The Messenger of Allah (PBUH) said: If anyone goes out from his house after performing ablution for saying the prescribed prayer in congregation (in the mosque), his reward will be like that of one who goes for hajj pilgrimage after wearing ihram (robe worn by the hajj pilgrims). And he who goes out to say the mid-morning (duha) prayer, and takes the trouble for this purpose, will take the reward like that of a person who performs umrah. And a prayer followed by a prayer with no worldly talk during the gap between them will be recorded in Illiyyun." If it is graded as Sahih, what is intended by "And he who goes out to say the mid-morning (duha) prayer." Isn`t it better to perform supererogatory prayer at home?

What is the interpretation of the narration about wife's abstaining from going to bed with husband? And does it apply to both spouses?

A son consigned for his father`s zero-interest loan in return for being loaned a portion of it. The son managed to pay off that portion from his salary to the party granting that loan. When the son asked his father to pay off the whole loan, the father refused and told him to pay it himself because the Hadith says, "You and your wealth belong to your father." What is the ruling of Sharia on this?