First I would like to tell the developers good job on building a great foundation for a game.  
Now I have some questions.  I haven't delved into the code so I've only made changes to the XML files.  Can I make the following changes?
#1.  Add a resource.  I want a fourth resource, mythril.  From what I can tell I would need to make a new tile for the map and a new icon and location for the icon on the screen.  Would I have to get into the code to do this?  I've already changed gold to iron so my resources are iron, stone and wood.
#2.  I want my summoner's EP to be used to summon instead of gold.  I've made the change so gold is no longer used, but I can't figure out how to make the summoner's EP be used instead.