ahle bayt

Q: I've been taught to follow the Quran and Sunnah. Many hadiths I've read say to follow Quran and Ahlul Bayt. Are those weak hadith or are there hadiths that say follow the Sunnah as well?

Q: Why are the descendants of only Hazrat Hasan and Hazrat Husain (Radhiyallahu Anhuma) considered to be the extended bloodline of Prophet Muhammad (Sallallahu Alaihi Wasallam) considering Hazrat Fatima had other children too. Adding further, Hazrat Umama also had a child. Is it an exceptional case?

Q: In the books of ahadeeth, there are numerous instance like Hadeeth e Kisa or the incident of Mubahala where there is only the presence of Hazrat Fatima recorded. Whereas Prophet Muhammad (Sallallahu Alaihi Wasallam) had 3 more daughters, and during these two incidences at least 2 daughters apart from Hazrat Fatima were alive. Apart from these two incidences, there are many hadeeths in which the position of Hazrat Fatima is extolled and there is hardly any reference of Ruqayyah bint Muhammad, Umm Kulthum bint Muhammad, Zainab bint Muhammad. They also don't feature among the Ahle Bayt, wherever that reference is found in the books of hadeeth.