@Enrique the main problem you seem to be having is that you are not aware that there is a frontend and a backend to NodeBB. You have to wire up the controls from the ACP and make a call to the backend (via websocket, for example), and then you can call server side libraries.
I have the write api plugin installed as well as the question and answer plugin. We are successfully creating topics and posts. Is it possible to create a topic as a question? I tried adding isQuestion (equals 1) to the POST body when creating the topic but it was ignored. Would the write-api have to be forked and updated to support the optional value of isQuestion? It seems clear in the question and answer plugin that it doesn't create/expose any write api of its own.