I kind of want Sandru to be a mentorish kind of figure, even if there's no game mechanic behind it. She looks up to him, but also wants to defeat him! He represents her Life Miniboss...she must exceed him to progress farther into the level!
Binder, yeah, I think that's best. I'll keep the white hair, because I like the idea of her fox form being white. And also, I agree about the flashy eye thing. I think she takes perverse glee in freaking out folks who aren't from Sandpoint that way.
As for relationship...friendly!