Dr Saab, if a hadith/tradition does not violate common sense or a Qur'anic principle, we are still left with hearsay narrations by people who never met the Last Messenger, written 250 years after his demise. Aesop has some nice stories that do not go against the Qur'an so it is possible for other people to make up sayings that do not do so and attribute them to the Messenger.
Whenever a Messenger went to his people, it was always ancestral traditions that prevented some/the majority from accepting the ONLY MESSAGE Allah wanted them to follow. Hadith, in agreement with Qur'an or not, are making us do the same; follow our ancestors.
As there is no verse in the Qur'an stating that we can follow the hadith and sunnah of the Messenger, and many that say only follow the Qur'an, then principle number one and only should be:
1. Nothing but the Qur'an-period!
For those ancestor worshippers, the Bukharians, here are a few Hadith of Allah:
4:87 Allah! There is no god but He. He will summon all of you on the Day of Resurrection about the advent of which there is no doubt. Who can tell you a more reliable HADITH (saying) than Allah
7:185 Can they not see (and correlate what he tells them with) the Dominion of the heavens and the earth and what Allah has created? Does it ever occur to them that the end of their own life may be near (hence the time to make the right decisions is not unlimited)? What HADITH besides the Qur’an, are they going to believe after him?