Ghost Rider's Satan confuses me too. It seems Hellstrom's gone back to being the son of real, honest-to-someone-other-than-God Satan in his MAX mini-series, and Ghost Rider appears to be tied to Satan and Judeo-Christian angels rather than lesser demons like Zarathos now, but I can't recall ever seeing GR's Satan referred to as anything but Lucifer. So now I'm left wondering: different names for the same guy or different characters entirely? We've already seen plenty of Satan's other pseudonyms go to different characters, like Mephisto(pheles), Beelzeboul (or some variant on Beelzebub; not sure on the spelling), etc.
The sad part is you're right, all of the confusion can be attributed to Marvel's inconsistent support of the idea that their Satan = the Judeo-Christian devil for fear of being too controversial or whatever.