captives

Asslamualaikum,I received(information) this incident and the quranic verse frm a non muslim... can u plz verify if its correct and also i did not understand the meaning of the ayat can u plz explain the following ASAP.....jazakallah. ""Muhammad sent a military expedition to Awtas on the occasion of the battle of Hunain. They met their enemy and fought with them. They defeated them and took them captives. Some of the Companions of Muhammad were reluctant to have intercourse with the female captives in the presence of their husbands who were unbelievers. So Allah sent down the Qur'anic verse: (Sura 4:24) "And all married women (are forbidden) unto you save those (captives) whom your right hands possess." (Abu Dawud 2150)"""

Dear Muslim scholars, As-Salam Alaykum! I know you all share with me the same feelings of a deep-seated resentment over what is happening to the prisoners taken by America and its allies in Afghanistan. They are being exposed to all forms of inhuman treatment. Does this go in line with democracy and human rights which the Westerners claim of being the advocates? So scholars, please shed light on what should be the fate of captives of war. Jazaka Allah Khairan!

Is it permissible for me to perform Hajj on behalf of my brother who is now held captive? Also should I ask his permission before going for Hajj on his behalf?

Is it lawful for Muslims to kill their enemies who have been captured during war? Or should the Muslims bargain with the leaders of the enemy to exchange captives?