You mean, like monasteries? I mean that not as a slight to the RC church, but as a demonstration of the point that cults are basically in the eye of the beholder.
No, the isolation is a basic tenet of the religion. Monasteries are an off shoot of a larger religion.
No that's not what "isolate its members" means. It's a reference to a cult's tendency to encourage new inductees to sever ties with non-cult members.
Not physical isolation, social isolation.