I've been watching Hannibal from the start.  I, too, was somewhat put off by the lack of the Hannibal character's involvement in the early episodes.  However, Mads Mikkelson, even in the little footage we got of him, was fascinating.  His acting is very subtle but almost anything he did was fascinating and made me want to know more.  I realized that a show titled Hannibal would have to bring that character more clearly into the action and that's exactly what's happened.  The last two shows have had some compelling moments spotlighting Hannibal.

I understand that the show is "on the bubble" at NBC.  Rumors abound that a cable enterprise, A&E is most frequently mentioned, is interested in picking up the show which the stories I've read indicate is available for a pittance compared to other American network television programming.  The trouble is that this show is a slow build which U.S. TV audiences don't usually tolerate.  Each week another layer of the onion is peeled back revealing another facet of Hannibal's life.

Although critical response has been good, the show has dropped to under 3 million viewers.  I suspect if it went to cable it would get a lot more attention and become a darling not only of the critics but of viewers as well partly because cable is considered the hip venue for TV and partly because cable viewers have different expectations of cable fare (i.e. are more tolerant of unusual content, concepts, and execution).  I guess we'll see.

Accordiing to Wikipedia, each season of the show will be limited to 13 episodes and season 4 would cover the events of Red Dragon.