I agree with all that with a couple of caveats. I have seen some very flexible girls who could externally rotate the shoulder, if I have that term correct, to an extraordinary degree. Not that that invalidates the rule that being a little more open on the rise helps. On your assertion that "correct" mechanics need to be used, well, yeah, but just like in hitting, their are plenty of people with resumes who disagree on what those correct mechanics are. I agree there are mechanics that are the most efficient and safe. I'm just saying words like correct, or in hitting the popular word is "proper mechanics", imply a level of agreement across the sport that just isn't there. We in the sport can't even agree on the definitions of terms. That's why I try to avoid words like closed, open, figure 4, leap and drag, stepping style etc in favor of linking to a clip and saying, "there, pitch like that". You standing in front of someone teaching have the advantage of making sure they understand your words. Not so on the net.
By the way, I see where Mike White was recently honored. 9/23 SEPTEMBER 23 UPDATE
Mark, there are correct ways to throw and incorrect ways to throw. Incorrect does not mean you can't pitch. I watched the College World Series and saw terrible mechanics by some so called "elite" pitchers. They got there because they were big and strong and overcame some of their shortcomings. There are many people out there teaching pitching that prescribe a lot of the "wrong" ways to throw, so that there is so much information that I can see why you think there is no agreement as to what's right and what's wrong. There are plenty of girls who should not be pitching because they really don't have the athletic skills to do it correctly. Therefore, pitching coaches have come up with crazy drills and styles to accomodate these kids. These teachings have cropped up everywhere and what you have are the girls that are capable of doing it properly are being taught the nonsense that was made available for the not so gifted athlete. I think that you may have been exposed to a lot of the Ernie Parker and other guru's methods and can't decide what is right or wrong.