Zoro's displayed the third type of Haki, i think (possibly. There was an instance at Sabaody where he scared off a gang of bounty hunters just by looking at them, but that could be interpreted as normal intimidation)
On my Hancock prediction, i'm thinking more in terms of overall plot than in-universe logic (i'm thinking what would an author do with someone in her situation?). If she continues to survive unchanged, she has to get further romantically entangled with Luffy at some point, something that really doesn't seem to fit Luffy's character. Hence she has to be "dealt" with somehow.
And as for Coby, think about how far he's come in 90 days, from timid little cabin boy to Efficient Marine Officer w/Haki. Who knows how far he could go with a span of time 8 times as long as that?
Monster Hunter: pissing me off since 2010.
