what file i need to edit to change ship and building,research cost,armor,dmg,hull .
All start with the player entity file... from there, everything evolve like a tree...
the player entity link to ship entity who link to ability entity, who link to buff... ship entity link to .mesh too, who link to texture and harpoint, these last an link to particule effect...
So, the best thing to start is read the player entity file and from there, follow the way to what you wish to change...
In fact, the main file is somehow the galaxydef file, somehow the root of the tree... but for little edit, you don't need start there... but if you wish add militia, planet, etc, it is the starting place...