Re: Beginners with delusions of grandeur...
I'm currently going through this with a six-year-old. We've been working on katate kosa tori kokyunage, and he's found that he can stay on his feet and keep from being thrown. Between the difficulty of getting under his center (I'd about have to drag my knuckles on the floor) and my desire not to overstress his ukemi, I just can't do the throw reliably without using force in a way we don't encourage.
I've just been saying "Okay, that was nice. Now can you let me practice the throw, and you practice the ukemi?" But I'm only an assistant teacher. It would be harder to take this attitude if I were the main teacher.