questions on "moderating".

I'm not sure how this can be setup, what the options are, so will ask these questions:
Let's say there's a member who gets into it with another from time to time. Each has great value to the forum, but one tends to follow the other and bully, poke and prod to get the other to react.

Can a member be put into a group and the group set so that posts by anyone in the group need to be "approved"?
Can this be done where they could post freely in one area, and not others without "approval?"

We have just a small handful, say 3 or 4, where we'd like to have a probation or approval for their posts. This might prevent the mix-ups. If they know that any nasty posts will simply be not approved, it might make them think before typing.

But we want only a select few to have to be "moderated". Can people be members of multiple groups, say a ladder group, and also a group called "moderated" for example?

I guess I misunderstood Bruce a while back as I thought he said something about being a member of more than one group. Sort of like Active Directory - security groups.....