Like with the demo or something?
No. You need the full game to make one, and to play them.
No, you need the full game for all the files for making them map.
I personally doubt anyone would want to play a mod made by someone who does not own the game, even if it could be done.
But to answer your question, you cannot. You need all of the files which the core game has to run the custom stories, and you need all of the assets to make the maps.