First of all you should really learn some scripting. I'm currently writing a nice tutorial on adding/replacing units,vehicles,weapons,buildings but it is far from done right now and the first release will be in german. I must say that it is fairly easy as long as you use common sense and just try a few things without being to dissapointed i it doesn't work out right away. Learning by trial & error that is. But it consumes a whole lot of time.