Authentication

Practicing on Dhaeef Ahaadith regarding virtuous deeds and actions

Q: Are daif hadeeth virtues of surahs and adhkar 100% guaranteed or one can hope that after doing them Allah will give them and can one just stick to sahih and hasan hadeeth like virtues of surahs baqarah and imran that whoever recites them they will intercede for him and hasan hadeeth like surah mulk. 

There are some daif hadeeth like recitation of certain surahs in night like surah Yaseen, Dukhan, Rahman Waqiah and Hadeed, these three surah recitation anytime during day or night on day of qiyamah he will be called from the people of jannatul firdaus. If these daif hadeeth virtues aren't 100% guaranteed, can I stick to daily recitation of one juz and Musabihaat surahs before sleeping along with Surah Mulk and Surah Sajdah.

A fabricated hadith regarding a dua at the time of azaan

Q: Is the following authentic to be read at the time of azaan: 

مَرْحَبَّا بِالْقَائِلِينَ عَدْلاً مرْحَبًا بِالصَّلَوةِ وَأَهْلاً

Khateeb Baghdadi (rahimahullah) reports in a narration that Nabi (sallallahu alaiyhi wasallam) has said that whoever says the above the moment the Muazzin proclaims the Azaan; 20 000 virtues are written down for him; 20 000 sins are forgiven; and 20 000 ranks are elevated for him. (Jaamia Al Hadeeth, As-Suyuti, Pg 313, Vol 7)