7 missing kids in what must be a relatively short time-span and within one specific area should have all law enforcement working full-time. At least it should have been mentioned before.
I don't care what's the deal with Caan it seems quite clear that he does not want to be on the show anymore. They've established quite a good core cast, use those people more and let him go. Chi McBride can take over for the usual carguments, although I don't see Grover allowing McGarrett to take over his car. The writers will have to come up with another bickering-scenario. That shouldn't be much harder then coming up with excuses why Danno isn't around on a regular basis.