Doesnt it also mean the bread is okay? From my understanding 그래요 can sometimes be used like 괜찮아요. Or is that wrong?
As what I know, 그래요 is not used like 괜찮아요. It's more like "really?" = 그래요? 그래 as the answer means something like "right" or "yeah". Maybe regarding to the translation in this particular lesson, 그래요? literally means "is it like that?"
Hmm.. depends. You can respond to 'How are you?' with '그냥 그래요' which would translate as 'just like that' or in a conmon English expression; 'Im okay' or 'Im so-so'