Adventurers of the Carotian Union was conceived as a series of interconnected stories, each of which is a complete adventure in itself.  Each may be enjoyed independently, yet each moves the questors toward their final overarching goal, the rescue of Eliander, the Lost Prince of Thalas.  If you were a Tom Baker Dr. Who fan, the stories relate to one another in the same way the stories in the Key to Time series did.   
Like all the stories in the series, The Chalice of Life is an ensemble piece. Mistra, the heroine, is more a first among equals than a main character. Although the series features some fairly intricate plotting, the development of the characters and their interrelationships is extremely important: in many ways, Adventurers is telling their stories as much as the story of the quest itself. Figuratively and literally, these seven extraordinary beings become the progenitors of the "new race of sentientkind" it will take to make the Union thrive.  I like to think the answer to the question "Are the stories plot-driven or character-driven?" is yes.
  
 In each adventure, the questors set some injustice to rights, thus saving everything from a single soul to an entire civilization. (This is what heroes are supposed to do, right?) Tackling each task set before them strengthens and perfects the questors both individually and as a unit. More importantly, in each adventure, the questors are given an opportunity to secure a piece of the magical grid into which the artifact that will free Eliander must be set before its power can be released.