Businesses would be a good idea. Adds more depth to the game.
Hiring other PCs won\'t be, because people don\'t want to have their characters do an hour of work, what\'s the player going to do.
So paying NPCs is a good idea.
As far as \"how to go about it\", Xandria has the best idea.
Item creation, ok: Only created by smiths or dropped by monsters.
But they also need to somehow be removed from play. Otherwise they will accumulate.