RB's actions were discussed D2 iirc, going to look around there now to see if there's anything new we can interpret from it. Though, I don't really think Dake's scum, since it's highly likely he's a Commuter thanks to Tanz's investigation.
Also, now that you mentioned it, Dake's character is Patchouli. It seems weird that Patchouli of all people would be scum and killed her friend's sister. Of course, this is all by flavour so relying on it too strongly isn't what I would recommend.
Assuming pieguy isn't derping around and reinterpreting roles, there's no way Dake can kill as a Commuter.Wiki wrote:
The Commuter is a role that "leaves Town" each Night, thus making them ineligible to be targeted by Night actions. By extension, they cannot use any Night actions they may have.
Also, now that you mentioned it, Dake's character is Patchouli. It seems weird that Patchouli of all people would be scum and killed her friend's sister. Of course, this is all by flavour so relying on it too strongly isn't what I would recommend.