What does it mean when spheres are opposed? Does it mean they're mutually exclusive and that taking a trait in 1 tree locks the other one out? This is what I guess it does, but I couldn't find the explanation.
Further small note: Fire doesn't seem to have a noted opposed sphere (should be water, as that one has fire noted as opposed?)
And the primal sphere doesn't seem to have a benefit for having all your 'sphere traits' be primal traits. Is this intentional because they're stronger than the others?
For Opposed Spheres, it seems to be purely flavor. It's not normally possible to take Traits from Light/Dark if you're on the opposite team, so listing direct opposition seems redundant.
I also could not find a benefit for having all Primal Traits, and am inclined to agree that their innate power is the reason for this.