...A Hard difficulty setting for the game could place Sol closer (or inside) another race's sphere of influence.
Hard difficulty! That's brilliant! But wouldn't defending the star base from Ilwrath Avengers regularly become kind of tiresome? Maybe you should be able to station up to 12 ships which fight as awesome AI at the base to protect it while you're gone from occaisional Ilwrath, Slylandro, and possibly other things.