A nice and useful tool!
Regarding your further intention:
"Changable system icon configuration for showing information such as economy, species, government, etc"
I think just colour-coding the systems (red to blue) would be more appropriate to perceive the info on government or economy. In this case, the connecting lines would have to be changed to white or gray, since yellow would be used the in the red-blue coding range.
In this case, the colours will show one info type at a time (gov, economy) not all of them.
The idea is the configurability. If you want what you have described you can. Yes the colour of the lines will be configurable too. (not that I see an issue (yet) with colour of the systems compared to the line. I think they will be distinguishable.) As for the type of info displayed that again will be up to you. You can display more than one at a time by having an icon or coloured circle for the system icon and sub icons, smaller and offset (think subscripts and superscripts), or coloured symbols (symbol for one peice of info and colour for another) but generally the more info you put on screen at the same time the closer the zoom will have to be to see it all. (See the icons used by Clym's vector maps to see what I mean.) Colour range will be configurable too. If you want red to blue you can if you want green to magenta or a specific palette you can have that as well.
Well this the aim. Implementation will be the hard part.
Oh, Here are some icons for species I have created:
Edit: changed link to actual image.