Is it obligatory for a Muslim to follow a specific one of the four madhhabs, and if not, how does he choose rulings? Is it true that some hadiths unknown to the four imams play a role in rulings? Does the book Fiqh As-Sunnah contain weak hadiths, and is there a corrected version of it? What is the opinion on the book "Al-Fiqh fi Al-Madhahib Al-Arba'ah" and Ibn Qudamah's book Al-Mughni?

Obedience to Allah and His Messenger is obligatory upon a Muslim. If a matter concerning his religion becomes unclear to him, he should ask someone whose knowledge and piety he trusts. The common person has no specific madhhab (school of thought); rather, his madhhab is that of the one who issues him a fatwa, and he must choose the most knowledgeable and pious. As for the discerning student of knowledge who has reached the rank of discernment or following [a particular school], he is obligated to adopt what he finds most preponderant among the proofs. The mujtahid (independent jurist), however, is not permitted to engage in taqlid (imitation); rather, he acts upon what he appears to be most preponderant to him based on evidence. The omission of some hadiths by some imams does not detract from their stature. The book "Fiqh as-Sunnah" is not a hadith book; rather, it is a fiqh (jurisprudence) book that may contain weak hadiths, and "Tamam al-Minna" by Al-Albani clarifies its weak hadiths. The books "Al-Fiqh ala al-Madhahib al-Arbaah" by Al-Jaziri and "Al-Mughni" by Al-Maqdisi are beneficial for students of knowledge.