I like all that except grove. Seems too plant-like, and it would be better for them to be distinct from dryads. Foxes are "skulks" or "leashes," but those don't seem right, either. What about pack or pride?
For some reason, "haze" really resonates with me.
Do we need a "grove dependent" type ability?
Definitely.
Just modify the SRD Dryad's Tree Dependent...
Grove Dependent (Su): A kitsune kasumi is mystically bound to a grove of trees and must never stray more than 300 yards from it. Any who do become ill and die within 4d6 hours, they also sicken and die if all of the trees in the grove are killed. Multiple kitsune kasumi can be dependent on a single grove, forming a family group called a haze. A kitsune's grove does not radiate magic.