To be 'expert' and become an authority on any teaching, it is an imperative to study the fundamental and original authorship of a teaching and follow critically its content. To deviate from a teaching for one's own political or financial gain is an aberration of the original teaching and intent. This is trus in any discipline. Sure, you are free to create your own offshoot, but never as a replacement of the original. This is the main point of Nichiren's discussion in this part of the Gosho