Clarification needed re grafting
Is "Grafting" just a fancy term for slicing a queen cell off the comb and (somehow) attaching it to a frame in a nuc?
No, grafting is moving very young worker larvae, from their worker cells, into artificial or natural queen cell cups (the basic beginnings of a queen cell). In a pinch, I once made a strong colony queenless, then after they had begun a nice crop of emergency queen cells, I replaced the native queen larvae, with larvae of my own choosing. That was how I used natural queen cells to graft into.