I would first like to say I have not been this excited about a game since Master of Orion II. That said the one feature that I would love to see in any tool kit would be something that handles the economics of the game. Something that when a new item is made you can see not only the current form, but how it is connected to other items and how it affects them. Any items that have same name should be compatible automatic, or the name changed to another version. Example the stock game might have "meat" but modded items might expand upon this with Deer meat, or any other animal/creature, but the "Base" item meat would govern the range of effects that might be used, this would keep things closer yet allow for more combinations. The end result would be that you can make a base item that can be used to create another item, either new or already in game but see just how it affects all that is along the path. Example grain that can either grow a plant, or be ground to flour, that is then connected to bread, that is connected to health affects or hunger affects, or happiness. But a smooth flow chart would be the end result, be it item or creature, This would also allow for a way to see very quickly that the goblin might carry meat over bread since he prefers meat to bread. The item and effects could be seen at a glance and anytime you wanted to change or add an effect you could do so for a class of items rather than having to do each one individually. Food items could be grouped such that cooking them changes them all in such a manner. Adding poison changes them all if there are not counters present already. An item that is used to repair a sword you make once then it affects the whole class and you can see very quickly just what it does. With this tool the next step for economics would be some way that the game does not revolve around the player, then as items are added it would be easy to see if they are going to be cheap and plentiful or scarce and expensive based on the in game demands. This and a dynamic price system for items rather than a static price based on a barter skill. But this has to be set up at the creation of a game, not an after thought. With the additional tool function of a flow chart it would be easier to make it happen even as an after thought.