There is a very handy link at the bottom to email feedback on what is missing. Please let us know where there are gaps and we can discuss here and improve the docs for all.
As far as the API key’s go “correct” is working. Now if you mean how you structure the access for those keys and how many key’s you setup and what for is more of a philosophical thing that Epicor Help wouldn’t be able to help with. That’s a far more personal question.