Billboarding is texturing a plane (it doesn't need to be an animated texture) and pointing it to the camera at all times.
I gave some tips about this at the
TGC Newsletter #63
How far you take the skysphere, well, is up to you! You could be colouring those background stars, or add some background nebula-type colouring pattern, so it is not all black & white.
The stars could have different brightness, and not all of the same size and colour. If this is our Solar System, then it would be better if the background stars resemble the real stars in our galaxy, that is, position and appearance.
It also depends on how far are you allowing the player to travel, as Serial Velocity shown, some try to go to the deep space.
About the dynamic media, well you would need some shader that not only performs as you want (halo, etc.), but also allows the changing of the base colour. I would leave that for a second phase ( I have been myself working a lot of time and I haven't implemented this yet, although it is about time ).
I know my initial suggestions may sound basic, but I would start with those simple exercises, and then think about travelling to some other galaxy