Full thoughts, yes, certainly. They generally speak whatever languages are spoken around their eggs, though they can pick up others the same way people do.
They do go feral, but only in the sense that, say, people go feral when they grow up in the slums. Their priorities tend to be different than those of humans, but they pursue them in the same ways, with perhaps a little more propensity toward violence.
In England, they are harnessed at birth by a captain with whom they form a deep bond. They are more autonomous in China, and they rule in Brazil. They require training in the same way people do - to do a particular job, to execute military maneuvers, to have manners, and so on.
And they are absolutely awesome.
I have indeed had whiskey, and it will do very well. After the month I've had, I could do with a drink or two.