I agree with the sentiment above: the books should be treated as a novelization of someone's campaign, the way things could go, not as the way things did go. If you want to play Rikus/Sadira/etc. as PCs, maybe in an alternate universe where Rikus bites the dust in a fight with a Mekillot early on, knock yourself out--but whatever happens to Kalak/Nibenay/etc. should ideally happen on-stage, or what's a campaign for? [1]
Alternately, you can be the bad guys, and treat the novel events as "what will happen if you don't do something to change it." Save Borys! Overthrow Dregoth! Keep Rajaat locked up forever! Take over Free Tyr, and then the world!
Incidentally, Werebat, are you by any chance the same Werebat (Ron something) who used to post in rec.games.frp.dnd back in the 1990s?
[1] My sandbox leanings retort, "Not everything should happen on-stage, bozo, in a living world that doesn't revolve around the PCs," but then I remind myself that "DMs are allowed to invoke the laws of narrative to cause the PCs to stumble into important dramas which, strictly speaking, are none of their business." It's up to the PCs whether they want to get involved or not, but there's nothing wrong with giving the PCs a heads-up that Kalak is in danger rather than presenting it as a fair acompli. In GURPS terms, all PCs can have the Weirdness Magnet trait for free if they want it.