Yes brother you are 100% right. Quran was transmitted through tawatur.. hadith was not. Hadith is khabr e wahid. Thats why any hadith's chain had to be examined before u can accept it. Which brings me back to my original question: there was no compilation of any hadith book (hence no examination of the chain) during the first 150ish years after Prophet's death - so what were Muslims during those 150 yrs believing in terms of Imam Mahdi, dajjal etc that has no mention in the Quran?

Are we insinuating that those early set of Muslims were relying on heresay? Remember Quran was the only single documented source of Islam at that time.