[Mike L]

John,
I think your problem is you are conducting your crusade in the wrong spot. Everyone here agrees IHC is a problem and needs to be called. We really don't need studies showing us the potential for danger, or some therapists opinion it's dangerous and all the other stuff you keep bringing up. We get it already.
Unfortunately, from what appears to be your point of view, it's not being called enough. And why is that? Probably because you don't agree with the general officiating philosophy that a foul, any foul, must be big, obvious, and no doubt about it before the flag flies. The great majority of the officials here, upon viewing your video examples, lean toward "no call" because the videos don't meet that standard. Yes, they are bad hits. Yes, in some of the examples the player was injured. But the angle, or video quality, or where we see the initial contact does not bring them to the level of being called. Like others have said, we can only call what we can see.
So, if you want to change that philosophy of when the flag flies, if for IHC you want it changed to anything that comes close to initiating contact with the helmet, you really need to start with your local assoc, perhaps your state rules interpretor, and eventually the NFHS itself. Until then, you are not going to convince anyone here to go against what and how their assoc is instructing them to do things.