These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Why is the Rider so incredibly psychotic in the film? Johnny's been keeping him locked away. He hasn't had any fun in a long time, and suddenly he's been given carte blanche to do whatever it takes to find Danny. Let the slaughter begin!
Could also explain why Johnny himself acts so absolutely friggin' nuts through the whole movie, and actually seems to calm down during the period when he's de-powered. It's repeatedly said that the fallen angel that inhabits him is literally insane.
The Rider's line in the first trailer released on-line also shows that in addition to being completely out there in terms of his brutality, he also has a disturbed sense of humor when he kills someone.
Nightmare Fuel: Ghost Rider has been turned into a complete psychopath. His movements, rather than being methodical and stern like you'd expect, are erratic and generally unhinged. He doesn't speak much, either. He just laughs.
Blackout's corpse-like appearance and his ability to dissolve people/things just by touching them.