Hi JP Shadow,
In answer to your questions, you need to demonstrate competence in the form(s) you wish to teach.
Certification, permission to teach, does come from existing schools and masters. The master or his representative will acknowledge that you know what you are doing.
A certificate usually specifies what it is that you are qualified to teach. How this is expressed varies from school to school.
[This message has been edited by DavidJ (edited 06-17-2002).]