I may have missed it but I was trying to figure out what a class only having a single sphere of influence means. Is it
a. That class AND the base species only have abilities from a single sphere
b. That class only has abilities from a single sphere but the base species can have abilities from other spheres (meaning any class that takes only a single trait from a single sphere automatically qualifies)
Also, a follow up question, I would assume when making a new class from an old class if the new class added traits from sphere A to a class that was taking abilities from sphere B that the new class would not qualify for the single sphere bonus as it has sphere traits from 2 different spheres even though the new class only added traits from a single sphere.