I read and watched.
While I agree on a lot of the points, such as nosebands should not be used to clamp the mouth shut, I can't help but think it's all just a commercial for Dr. Cook's bitless bridles!
Maybe it's because I learned to ride before the whole natural horsemanship/ bitless thing became popular, but I have no problem with bits used with sensitive hands. But certainly if your horse goes good bitless, go for it! If you horse goes good in a bit, that is great too!
I try to have very sensitive hands. Am I perfect, no, but I really try to have a light touch on the bridle and I ride with very little contact. If the horse sneezes or trips, I usually loose my reins, that is how light I am holding them. I have even been known to ride with things (such as mechanical hackamores and curbs and tom thumb/ argentine snaffle type bits) that people on this board seem to hate. But I have good luck with them, and I think my horses are pretty content. If a horse isn't content, then I am a BIG BELIEVER in changing your bitting (or bitless) arrangements until you find what your horse goes well in. I have a whole box of bits and hackamores of different types and I actually enjoy trying different things until I find the "perfect" bit for the horse I am riding.
So yeah, if your horse is gapping at mouth, then please try out different bits, hackamores, Dr. Cook or whatever, to find out what your horse is comfortable with. Don't just clamp his jaw shut. I agree with that. But do I think there is a fundamental problem with using bits? No, I've actually had really good luck with them.
If I wanted to, I could ride my horses in their halters, the mildest snaffle I could find, or whatever. The problem I run into is that I want respect and finesse. I notice that if I ride in the absolute mildest head gear I can find (say a halter or regular snaffle), then the horse dives for grass, ignores my finer cues, etc. They just seem to loose respect for the head gear. If I move my headgear up just a notch in the control department, then they respect it more and I actually have to use it less. So sometimes I think the trade off is worth it in that you actually have to use the bit or headgear less, because they respect it. If they don't respect it, then I have to nag on them, such as if they dive for grass, want to go faster than I want, etc. and I just prefer not to have to nit pick them.
So I think there is a fine line between respect and the "perfect" bit for the horse, and overbitting or underbitting the horse. Sure, you can ride in almost anything if you want to, but to get close to optimal results without overbitting or underbitting, takes a little experimentation.
Sorry for the ramble. I like talking tack.