Supremacy's spectral standardisations main purpose was to stop abuse of spectrals. Many of the first ghosts just chilled in the Malinor square casually chatting rather than doing anything remotely ghostly, then using their ghost powers to be invunerable in fights. Gravens, which are corporeal, were even worse. I saw one Graven that was part of a raider party.
I disagree with Jistuma's standpoint that RPing a spectral like a spectral damages their RP potential to the point of only event viability. Acting as paragraph 1 completely diminishes their purpose and the nature of their RP, they're just another set of special powers on an otherwise generic character. Character RP is what you make of it. If you look at The Eternal Librarian, you've got a character that interacts with the playerbase but is still undeniably a ghost. You're not going to go down da pub for a drink with it. However, it's an almost integral part of RP in the Hael'unor library now.
I'd always disliked Gravens, I viewed them as the most heavily abused of the character types and I commend your attempt to update them without compromising what they are in the first place. My one concern is how you require them to be together: this kind of forces them into another player antagonist group, a sort of Graven Guild. While I understand this approach gives you a degree of oversight, I feel the forceful amalgamation of future Gravens isn't the right approach.