There's no copyright on names likes 'terran', and 'terraner' would be fine. There's no copyright on 'Earth's Defense Force' or whatever army names either as far as I can tell. That would be a bit like copyrighting the name 'Johnson' because you're using it for your maincharacter ... can't be done as far as I know, unless it's like the name of the game (e.g. Max Payne). Anyways, so far so good, I like the screenshots,

Cheers