A weak example of this: someone from a society that doesn't have any explicit moral rules, i.e. 'Ten Commandments.' They might follow laws, but but the laws aren't explained 'A is the right thing to do' or 'B is wrong'.

I can see a case like this, but morality is a much broader idea than can be captured by a list of divine commands and similar such things. Even Christians, Jews, and Muslims would say that the ten commandments are just a sort of beginning, and not all on their own sufficient to be moral ideas.

Someone raised in that context would probably be strange, and kind of undisciplined, and probably pretty thoughtless about the consequences of actions, and might include only a small number of people in their 'circle of empathy'...but I don't think they'd be incapable of having friends/being nice.'

Huh, we have pretty different intuitions about this: I have a hard time imagining how you'd even get a human being out of that situation. I mean, animals, even really crappy ones like rats, can be empathetic toward one another. But there's no morality in a rat, and we would never think to praise or blame one for its behavior. Empathy itself is necessary for morality, but far from sufficient.