How about the number of Rakah in one Salat, calculation of your Zakat, Tayammum, Aitkaf, Ihram, Miyqat, diyah.
Brother, Mohammed peace be upon him came to preach the message and to teach the people how to practice and preform their religion.
He peace be upon him said; pray as you see me praying. also; ''Learn your rituals from me''
It is not about Bukhari , there is something called science of Hadith and reporters. Any Hadith lack of Isnad is rejected.
O you who have believed, if there comes to you a disobedient one with information, investigate and verify. Al-hujrat 6.
Tayammum:
5:006 O ye who believe! when ye prepare for prayer, wash your faces, and your hands (and arms) to the elbows; Rub your heads (with water); and (wash) your feet to the ankles. If ye are in a state of ceremonial impurity, bathe your whole body. But if ye are ill, or on a journey, or one of you cometh from offices of nature, or ye have been in contact with women, and ye find no water, then take for yourselves clean sand or earth, and rub therewith your faces and hands, Allah doth not wish to place you in a difficulty, but to make you clean, and to complete his favour to you, that ye may be grateful.
Rakah: The Quran does not specify any number of units for prayers. It leaves it to our discretion. Since there is no dispute on 2,4,4,3,4 (fardh), so this is more likely preserved by God.
Zakat: If you are asking percentage than yes, it's not mentioned but guidance for this is still there
6:141 He is the One who established gardens, trellised and untrellised, and palm trees, and crops with different tastes, and olives, and pomegranate —fruits that are similar, yet dissimilar. Eat from their fruits, and give the due alms on the day of harvest,* and do not waste anything. He does not love the wasters.
Example here is given of corps, eat from it, give due Zakat and don't waste. Means - give maximum or infect all excessive of your needs.
Hajj:
2:196] You shall observe the complete rites of Hajj and 'Umrah for GOD. If you are prevented, you shall send an offering, and do not resume cutting your hair until your offering has reached its destination. If you are ill, or suffering a head injury (and you must cut your hair), you shall expiate by fasting, or giving to charity, or some other form of worship. During the normal Hajj, if you break the state of Ihraam (sanctity) between 'Umrah and Hajj, you shall expiate by offering an animal sacrifice. If you cannot afford it, you shall fast three days during Hajj and seven when you return home—this completes ten—provided you do not live at the Sacred Mosque (Masjid). You shall observe GOD, and know that GOD is strict in enforcing retribution
[2:197] Hajj shall be observed in the specified months.* Whoever sets out to observe Hajj shall refrain from sexual intercourse, misconduct, and arguments throughout Hajj. Whatever good you do, GOD is fully aware thereof. As you prepare your provisions for the journey, the best provision is righteousness. You shall observe Me, O you who possess intelligence
[2:198] You commit no error by seeking provisions from your Lord (through commerce). When you file from 'Arafaat, you shall commemorate GOD at the Sacred Location (of Muzdalifah). You shall commemorate Him for guiding you; before this, you had gone astray.
[2:199] You shall file together, with the rest of the people who file, and ask GOD for forgiveness. GOD is Forgiver, Most Merciful.
[2:200] Once you complete your rites, you shall continue to commemorate GOD as you commemorate your own parents, or even better. Some people would say, "Our Lord, give us of this world," while having no share in the Hereafter.
[2:201] Others would say, "Our Lord, grant us righteousness in this world, and righteousness in the Hereafter, and spare us the retribution of Hell."
[2:202] Each of these will receive the share they have earned. GOD is most efficient in reckoning.
[2:203] You shall commemorate GOD for a number of days (in Mena); whoever hastens to do this in two days commits no sin, and whoever stays longer commits no sin, so long as righteousness is maintained. You shall observe GOD, and know that before Him you will be gathered.
Aitkaf - As far as i know it's not mandatory, If it is than first show tell me the verse of Quran declaring it mandatory, than i will try to research and find the answer.
Miyqat, Diyah??
Last line of your posts sums everything by itself.
"O you who have believed, if there comes to you a disobedient one with information, investigate and verify. Al-hujrat 6.
It's responsibility of EVERY believer (not just Hadith book writers) to investigate & verify, Surely they have verified but there is no surety that their judgement was right, after all they were humans. So, Today we can't verify the source but surely we can cross check either these Hadith's comply with Quran or not - no matter how much Sahih the book is but still that is not more credible than Quran.