Lightfire22000,
Some of your points are well thought out and valid; some are off-target.
Your criticism of schoolteacher certification is spot-on. The preparation is homogenized and process-oriented. Persons from outside this system have difficulty obtaining teaching certification, but that is partially as it should be. Many school systems are not primarily in the business of delivering content. Thus, school teachers generally spend lots of time on discipline, individualized educational plans, parent conferences, repairing the Ritalin fog machine

, meetings, pep rallys for the sports teams, and so on, but not so much on content. Many school systems do have teachers with very good content creds, but those tend to get shunted to AP classes.
In some areas there is a canon of knowledge that is needed in order to spend the first day on the job. A Physician's Assistant is not a junior Physician but allied. It is not reasonable to expect a PA to be able to beome a Physician through OJT. That rather Draconian memorization/lack of sleep/intense grilling/cut-throat competition that Physicians go through is not duplicated in the PA curriculum. Some may say that sort of preparation is outdated or even bad, but it produces people who can roll out of an on-call cot at a dead run when they hear a "Code Blue" at 3:15 am and begin treatment of the patient within 45 seconds of the code. Even for senior Physicians who are required to do that, it produces surgeons who are able, while repairing a seemingly minor hernia to deal with the aneurism that suddenly blows.
The certification cuts both ways in terms of level of education. One might have a PhD in Mechanical Engineering, but is in no way qualified to act as a bridge welder. There is an apprenticeship process required in which the welder-to-be gains the approval and acceptance of his peers. Frankly, when I'm halfway across the Chesapeake Bay, I don't want to have to think whether the guys that welded that bridge were trained to AWS standards - I want to just
know.
We could do a better job of defining standards, and skill levels, for professions. I, for one, would like to see university professors be able to demonstrate that they know
how rather than
what prior to obtaining tenure.