The Qur’an is the only obligatory hadith although the rest are a historical reference. It is impossible to accept them as a source of religious law without upholding Bukhari as a messenger of God. The Qur’an says that is complete and fully explained (4:13, 6:114, 7:52, 15:1, 16:89, 24:34, 26:2, 36:69, 39:27 and in countless other places). The Prophet’s duty was to deliver the Qur’an (46:9) and no Prophet was to be obeyed except by Allah’s permission (4:64). To obey the Messenger within his duty was to obey Allah (4:80).
Any hadith that contradicts or embellishes the Qur'an in any way is unacceptable. The rest are literally hearsay and may or may not be beneficial provided that they are not declared as religious law.
Does it not say to let Muhammad judge disputes and that the Wisdom (al-Hikma) was sent down with the Qur’an?
In ayah 39 surah 17 al-Hikma is identified as the Qur’an:
“This is of what your Lord has revealed to you of wisdom, and do not associate any other god with Allah lest you should be thrown into hell, blamed, cast away.”
The teaching of the Book and the Wisdom is incorporated in the reciting of the Qur’an (i.e. the Messenger’s duty):
“Allah did confer a great favour on the believers when He sent among them a messenger from among themselves, rehearsing unto them the Signs of Allah, sanctifying them, and instructing them in Scripture and Wisdom, while, before that, they had been in manifest error.”
Furthermore, it is Allah (swt) who bestows wisdom (not the Prophet):
“He grants wisdom to whom He pleases, and whoever is granted wisdom, he indeed is given a great good and none but men of understanding mind.”
(Yu/tee alhikmata man yashao waman yu/ta alhikmata faqad ootiya khayran katheeran wama yaththakkaru illa oloo al-albabi)
“And when you divorce women and they reach their prescribed time, then either retain them in good fellowship or set them free with liberality, and do not retain them for injury, so that you exceed the limits, and whoever does this, he indeed is unjust to his own soul; and do not take Allah's communications for a mockery, and remember the favor of Allah upon you, and that which He has revealed to you of the Book and the Wisdom, admonishing you thereby; and be careful (of your duty to) Allah, and know that Allah is the Knower of all things.”
Another example of the Qur'an referring to "the Book" and something which the Book brings:
“Certainly We sent Our messengers with clear arguments, and sent down with them the Book and the balance that men may conduct themselves with equity; and We have made the iron, wherein is great violence and advantages to men, and that Allah may know who helps Him and His messengers in the secret; surely Allah is Strong, Mighty.”
33:34 finishes the argument (instructing the wives):
“And keep to mind what is recited in your houses of the communications of Allah and the wisdom; surely Allah is Knower of subtleties, Aware.”
The ahadith are not recited. No other hadith is needed. Regarding Muhammad as judge, he was at that time the appointed leader of Islam (similar to those “in authority” (-9)) and he followed only the Qur’an:
“Surely We have revealed the Book to you with the truth that you may judge between people by means of that which Allah has taught you; and be not an advocate on behalf of the treacherous.”
Mention is never made of a Revelation additional to the Qur’an.
“I swear by the Book that makes manifest (the truth). Surely We revealed it on a blessed night; surely We are ever warning - Therein every wise affair is made distinct.”
“Alif Lam Ra. These are the verses of the wise Book.”