I have worked on the suggestions and thought I'd share the results:
- I had a hard time drawing a Skybox myself, mostly due to parallax errors in the corners and my inability to mask the transitions at the edges. For anyone searching, try Spacespace (http://alexcpeterson.com/spacescape). It does the job beatifully and I'm glad I stumbled on this. For the time being, I could get away with a single rendering pass, since there are no distant objects and the skybox is 10000 big, as suggested.
- The Skybox helped with orientation in a relative manner, like you can tell which way you are turning/looking. But what I needed was an absolute reference point, so I followed Prinz Eugn's advice and added a milky way band all arround one axis (It's actually tilted, but there is no way to notice, which I'm pretty happy about). The galaxy is additively blended over the background which works great.
- The galactic core on the side of the sky box further helps with orientation. I made it really bright and added directional lighting. sharp lighting really is the way to go, I more than doubled the intensity and it looks good.
- HUD: For now I added a line for each ship to indicate its current target. There is a lot to be done, like showing the estimated flight path (which should be curved rather than straight). Right now it is a wirefrime line, but I would want it to be a translucent and add a subtle glow effect.
- Particles: Added a threaded particle system. This makes things come to life, I added basic explosions and engine trails, but they are really ugly because I can't draw ;). I am working on that "star dust" thing right now, which will be hard because I cannot reposition particles right now to implement an infinite scrolling cube, only spawn new particles.