First off, I replied to your quote in page 14 at the very end, new page started too quickly. Second, low chakra didn't hurt his body, the sharingan puts a strain on it, which is why the eye bleeds and you see them holding it a lot after Amaterasu, it's not due to the lack in chakra.... do you even read the manga or just look at the pictures? The Uchiha's aren't known for "HUGE" chakra, they're known for sharingan, you're combining two different stories here, Kakashi couldn't use his sharingan for very long because his body isn't Uchiha, only his eye, the reason Uchiha's can use sharingan for a long time is because of their body having Uchiha blood, not crazy chakra