Any way to disable online aside from Steam?

The online features do nothing but detract from my experience in almost every way, is there any method that will let me boot JC3 up in offline mode but still have Steam online? I don't want to cut myself off from my friends, but I also don't want a huge-ass box perpetually hanging out in the corner of my screen telling me that TooManyCoons beat my ragdolling highscore.