It's left up to interpretation since there's no direct closure, but from the reaction Casey gave after being told her uncle had arrived and the look of interest/curiosity on the officer's face in response makes me think Casey had grown enough from the recent events to start the process of getting help.

It's left to interpretation. I think Casey is left to consider if she wants to go back to her abusive uncle in light of the Beast telling Casey that abused people are evolved superior humans.

My guess is that Casey will also develop a split personality as a result of her ordeal. This is heavily implied throughout the film with several shots of her speaking to other characters where only half her face is seen. I think it's hinting that behind this passive and weak personality she's letting on, there's a fierce side just waiting to come out. I think that maybe she and David Dunn with develop a sort of father and daughter relationship in the sequel with her playing as his side kick.