The cracked mind class feature refers to the veneficus esoterica, rather than the the scion. Minor copypasta.
Other than that, it seems fine. I disagree with it needing to be able to cast whilst raging - I get the image of them casting a few spells, channelling the divine power of their "deity" until it makes them explode in furious ecstasy and use their rage ability.
But that's just me.