യുക്തിവാദം പരാജയപ്പെടാന്‍ കാരണം?

Is it true that Quran has given permission to Muslim males to have sex outside their marriage (even after marrying four) with female slaves they posses??..Is this considered as not sinfull and not prone to stoning punishment .
 Is it true that prophet mohd(pbuh) married ' Safiya ' a Jewish lady ,without waiting for the specified period of iddah.Is it true that prophet mohd (pbuh) married his adopted son zayeds wife zainab after getting divorce from him ???.it is seen/evident that this incident has caused major embarrassment among his disciples , and to clear the air,Quran came up with many justification and specl rules exclusively in favour of prophet, evntly sanctioning him to marry 12 and his followers 4, and above that figures ,allowing unlimited sex with slaves they posses etc ...I humbly request you to pls clarify/comment on these 3 questions as I have been confused by these unusual incidents mentioned (mostly)in Quran when I read it ... thank u and aslaamalaikm...