I suppose a "no-touch throw" is possible when Uke is fully committed in his attack, and Nage lures & leads him to the point when whenever contact is about to be made, Uke's balance is broken.
Uke does need to be fully committed in his attack. Uke is lead by nage, the point where I differ from you description is that balance is not necessarily broken. I think it is possible to uke through a complete exercise without losing balance. I think it is possible to roll out forwards or backwards without having 'broken' anything. If and only if, the nage applies all of the principles inherent in aikido, the uke follows through the attack and is lead to a roll or avoiding manoeuver (and a possible atemi) simply to maintain co-ordination
That's my take on it anyway.