Help with storytellers

[cpmartins]

I'd very much like to increase the amount of quests I get when wandering the world map, similar to what this gentleman did with his series: https://www.youtube.com/watch?v=LxqmUnbiCw8. I asked how on his comments but didn't get an answer, and looked around on Storyteller.xml but couldn't get it working. In fact, pretty much all changes I made were completely ineffective at changing anything.