RE: oil in the radiator
I had this same problem with a Ford Windstar. The problem is either a bad head gasket, or cracked head. The Ford 3.8L is known for bad head gaskets, so I'm assuming that it was the head gasket. My daughter also had a Dodge 3.0L That recently had the head gasket changed by an idiot, and it was doing that also. Therefore I would assume that your problem is a bad head gasket. I agree, it seems a little odd that it would go from oil into antifreeze, and not the other way around, but trust me, if you keep driving it (which I did with the Ford) It does end up going the other way too.