Alright, now we're finally on the topic of space combat! This is kinda exciting for me, since this is the best part of 4X games in my opinion. As I said, the goal of the game is to make it very moddable and flexible, so I've been thinking of ways for providing users a way of testing their technology/designs quickly without having to go through all the preparatory steps (build an empire, research technologies, design ships, then finally see them in combat). I think I have a very good idea, and it will even let me add extra features later on!
The idea is that when you select a dataset to load (default or one of your mods), and click on "New Game", there will be a button in the galaxy setup named "Combat Simulator". The reason why galaxy screen is that at this point, it've loaded in all the relevant data, so it's able to do combat immediately.
When you click on "Combat Simulator", it will pop up a list of available battles to load. Those battles will be saved in "Battles" folder of the dataset, and will be .XML files. Each of those file contains the complete data for a space combat screen, including ships and their equipment, their positions on the battlefield, and any other items such as planets, asteroids, and whatnot. This also includes whether or not an empire is controlled by an AI player, and which AI it uses. So it will also provide users an easy way of testing the AI scripts for combat.
After you've selected an battle to load, it will jump directly to combat screen (which will be the exact same screen used in normal gameplay), and you can proceed to either watch (if all players are AI), or be involved and try out new technologies.
After the battle is over, it will return to the galaxy screen.
One other nice thing that this can provide is that people can create custom battles, and challenge others to beat them. This is similar to Chess challenges, where you're challenged to win in 2 moves, or move the right piece, or some other goal, using a pre-set game layout.
All in all, I think this is a win-win situation, it lets players to test their mod, and at the same time, allowing me to test new features in space combat quickly.