Other than waiting for debris, the only other way to train builders once all of the construction projects are finished is to start a new game. That situation is being worked on in an update to Village Sim, but it's still in development and a release date has not been announced yet.

There have been rare reports of it taking longer than a week for the Golden Child to take care of Puzzle 11. I have never had to wait more than a day, but I tend to leave my game running with my Palm on AC power when it's time for that puzzle - it seems to happen much faster that way.