Adding more workers to a upgrade in progress does (Speed)*(# of Workers).

Market Place, "Bazaar" be able to turn elixir into gold. Gold into dark elixir and elixir. Dark elixir into gold and elixir, etc.

Better 'defenders' AI. Defenders such as archers from the clan castle will stay inside the walls and won't be such easy targets to get rid of.

Patrols. Allow the barbarian king and archer queen to have a certain patrol route. But radius of vision is reduced to 3 blocks.