I made two “addin/plugin” in AutoLisp, and now I have a couple questions.

I am completely new in all of this, as you will conclude from my question.

1) .lsp-s are for Civil3D 2018 to 2025, is there some way to know that I am not stealing someones idea/program

2) What/which is best method to do data/code encrypting?

3) Any advice which "company" is good certificate authority (CA)…do I need to have my own company or something like that?

4) If answers to upper Qs are "positive", how to decide price and is it even worth it?