I don't think his off-ice stuff should be dismissed. There's enough smoke there for it to be something, but what and to what extent is impossible to know. Vancouver's own GM didn't throw Miller under the bus for the drama with Pettersson, he threw Pettersson, saying he's immature. The Rangers had Miller, they know exactly who and what he is, and they're trying desperately to get him back.
So again, I don't think it should be dismissed as nothing, but it's hard for me personally to say I know he's a bad guy or I know he'll be a problem when I don't really know what the real deal is.