I skimmed it once and it didnt really look playing. Honestly, as cool as the setting is I wouldnt want to run a game in it. As a GM getting everybody on the same page lore-wise is important, as it ensures everybody knows what the hell is going on. Half the fun of KSBD is filling in new bits about the world that you couldnt have predicted from older elements, hence its not a great system to run an RPG in.
As for what you could use instead, you could probably actually run some street-level shit in Throne using hacked Dark Heresy. Everything's there: Guns, Magic, Lasers, Demons, Backflips, etc.
All you'd need to do is come up with templates for all the Inheritors and you're good to go.