Fading Suns has an interesting setting, but there's several details that range from boring to nonsensical to infuriating. As such, when I ran it, I made several changes as follows:
According to the book, everyone, on all forty or fifty known worlds, which have only in the past half-century been unified under a common empire, speaks Urthish. This is so far beyond the bounds of credulity as to be impossible. In general, I think the worlds under each house should have a common language, due to common settlement history (though this will vary in cases of conquest and such). While still not that realistic, it's a reasonable balance of flavorful and gameable.