Authentication

Q: Is the permissibility of giving salam to Nabi (Sallallahu Alayhi Wasallam) on another persons behalf mentioned in any hadith?

Q: I was told that it was stated in a certain shaykhs bayaan that during the period when wahi was stopped, Nabi (Sallalahu Alayhi Wasallam) became despondent and wanted to commit suicide. According to my (ignorant) knowledge, I can never associate the mubarak countenance of Nabi (Sallalahu Alayhi Wasallam) with that of someone wanting to take his own life. Please clarify as the possibility of me being incorrect is very likely.

Q: I recently heard someone say that Nabi (Sallallahu Alayhi Wasallam) advised Muslims to change the clothes they'd worn during the course of the day for bedclothes when they retired at night. Is this true?

Q: I was reading an article in which a Mufti Saheb was describing that there will be 313 people with Imaan of the Sahaaba who will take bay'at on Imaam Mahdi's hand, and one Aalim told me it is not like that. What does our pious ulema tell about this?

Q: I am a revert to Islam, and I'm still learning..however I have come across some hadith, that contradict the teachings and character of our beloved Nabi (Sallallahu Alayhi Wasallam)..one example, the Prophet (Sallallahu Alayhi Wasallam) told his son to divorce his wife so that he (saw) could marry her for himself..another example is that he ordered the killing of 100's of Jewish men because they didn't accept Islam and allowed his men to rape the women of those slain men..my question is: Are all hadith true and authentic, and if not, which hadith should we follow?

س: كثر في زماننا أشد الإكثار - الناس الذين يقرون عن أنفسهم أنهم من الأنبياء، و يخرج من بعضهم الإستدراجات (و أكثرهم يرغبون بذلك المصالح الإقتصادية). أنا شخصيا رأيت في التلفاز الرجل الذي قال عن نفسه - أنه الرسول عيسى (ظهوره الثاني)؛ والناس الذين يقولون عن أنفسهم - أنهم الظهور الثاني للنبي عيسى - في زماننا كثير جدا (خاصة في الديار النصرانية). أظن أن ذلك من علامات تقريب يوم القيامة. هل هناك أحاديث ثابتة تخبر عن ذلك (يعني عن إكثار الناس الذين يقولون عن أنفسهم انهم من الأنبياء - قبل يوم القيامة)؟

Q: Is there any kind of hadith about Arab people like, Don't use any kinds of bad words on arab people because Nabi (Sallallahu Alayhi Wasallam) is an Arab, the holy Qu'an is in arabic and next language will be Arabic? 

Q: There is story about a sahabi who went out in path of Allah and prior to leaving said regarding his pregnant wife: i leave what is in the belly of my wife in Allah's care. When he got back he found that his wife had passed away but his child was found living next to the grave. Is this story authentic?

Q: Could the following be verified with a source please:

1. While memorizing the Holy Quran, If a person passes away the Angels of the grave will assist him in completion.
2. The place on the body which received hiding while doing hifz will not be burnt in the fire of Hell.

Q: Does it come anywere in the hadeeth that Nabi (Sallallahu Alayhi Wasallam) ever urinated while standing?