Gettting to know your characters is so much more important than plotting. Working out every detail of your story in advance, especially when you don't yet know your main characters, always seems a little too much like playing God. You're working out your characters' lives, their destiny, before they've had a chance to discover who they are and what kind of people they want to be.
The single most important thing a city can do is provide a community where interesting, smart people want to live with their families.