How far can you bend a note? 

That works to get started to at least tell whether you've changed the pitch. Ultimately you have to rely on your ears to adjust pitch accurately.

Sure, there are. I played them in the video. They're "in the cracks" between the notes of the regular chromatic scale, but they're real nonetheless and actually useful for expressive playing.

cannot be done....sorry

Don't be silly. You *heard* me do it in the video.

I remember trying to explain temperament to a new player who had just tested their brand new harmonica against an ET tuner. If I'd expanded on that and tried to explain microtonality on top of it I think their head would have exploded. That said, I don't think I've ever thought of using notes below the standard bends (although I do use quartertone bends both to play with the blue third and on the 5 draw). It's probably a result of all the customizers yelling at everyone not to bend past the floor. @@winslowyerxa8505

@@georgerismnot true at all. There’s too many example of great players using the 5 draw bend to name. Little Walter, Kim Wilson, Ronnie Shellist, the list goes on and on. You absolutely CAN use the 5 draw bend musically.