Narrators need the tools to enforce rules and take corrective action when mistakes or bugs occur, as well as the ability to create simple programs or scripts that restrict players or provide enhanced interactivity, preferably represented by visual queues that keep it all as simple as possible.

This should include:

-adding or removing cards at will from a player's deck
-unrestricted posting of images and the ability to resize them, or a thumbnail with larger version embedded in a link
-narrator only spell/grammar check ability
-interactive components, such as dialogue trees, coin flips, branching storylines
-dice added as a supplement to create diversity to challenges
-programmable stats sheets (it's more of an rpg thing sure, but it's definitely a want, if not a need)