Good stuff. Have you listened to the Beauty Brains podcast or checked out their forum? They were chemists for companies that made shampoos, conditioners, etc. and they talk about the myths and realities of a lot of the products in the beauty industries.
Also, IIRC, they mention that the whole alkalinity thing is apparently a myth except if you're going to the ends of the pH scale.
I do listen to them and bother them quite a bit with questions.
I do recall them saying this about the alkalinity, but the question really comes down to the degree of damage. Sure a pH of 9 isn't going to damage the hair like a straightening treatment will, but it does have an effect that can be felt and seen. In my mind the idea throwing around the pH of your hair for no real benefit can't be a good thing. They also talk at length about most damage coming from physical manipulation of the hair. The grittiness of baking soda along with the pH doesn't seem like the best idea when there are so many better options out there.