But I think you start already pretty steep, with one of the most difficult things (choices). It would be cool if you have a linear story where you guide the player from really easy things, to more difficult things. What I have in mind is something like this:
Player is somewhere with 1 other person, but something is blocking the exit. The NPC says “You have to open the editor, remove that stone, and then you can continue”.
Next up maybe add a bridge over a gap, add NPC’s, enable your sword through the editor, etc.
Next maybe he needs to receive a token to continue, so they have to edit the conversation. Like “go to the editor, and replace this text with ‘hero receives token ‘key'”.
That would be really awesome! This is a great idea :). But remark that screenplays should come last, it’s the most difficult part of this editor.