kakashi didnt question the fact that Lee was a hard work genius, he asked him self a rehtorical question. At least thats the last time he thought about it, he may have questioned it previously but i belive his last lines on the subject were somthing along the lines of "Lee really is a hard work genius?", perhaps there should ahve been an exclamation mark in there as well? Also on the subject of healing, its perfectly normal for people to be walking on a broken leg a week after they have done it, with the aid of crutches. Not so usre about push-ups but hey if 'Chopper' can do it with holes in his stomache i see no reaosn why a person who has trained intensivley for years cannot do it.

so to sum up, someone, anyone working hard or not, could walk after two weeks even if they suffered multiple fractures and breaks (to a certain point, but given Lee's physical attributes i dont see how its far fetched).