I think the new boss is the one sending the 'do it now' text messages. I also came up with a crazy theory during a 3am night feed that she is the real cult leader and is just using the James Purefoy character. Or possibly is second in command.
Re the Kevin/James question- definitely James.
I didn't think it was that gory A lot of the gore seems to be dead bodies, they don't show loads of violence on-screen compared to some other programmes. Also the gory details are a minor part of the story line rather than the main part, like those Hostel-type movies. Really, I've totally gone off violent things since the DDs were born but I can handle this show quite easily desensitised.