Another thing, where is Heji's guestbook? how come I had not seen it? is it out in the Anime? if not what's the manga chapter that appears in it? thanks.
Aside from that, I think the Boss is someone who is dying, due to the facts: one, his message to Vermouth:
From this we could speculate that the Boss needs Vermouth to his side maybe to attend him(?) also if we look at the underlined words, we could conclude that the Boss needs her most of the time to his side, owning to one day is too much freedom relatively for him.
Two, The Boss communicate with other members with email/messages, from this we could speculate that the Boss can't talk because of his illness or to hide his personality after taking the drug that shrunk him and changed his voice to a kid's voice.(?) (Meaning that Vermouth knows that, probably that's why she acts on her own sometimes -like hiding Conan/Haibra identites- although she is the closest to the Boss, yet, I don't think that the Boos is that stupid to let a woman -popular one- to act on her own without any observation UNLESS he is ill, or as I stated before he took the drug and shrunk, however there is a third possibility and that is the Boss knows what Vermouth is doing behind his back, still, not making a move.)