I am not sure I am ready to delve deeply into the topic of the teacher in vajrayana buddhism, but the idea might be of how essential the teacher is. I am not such a teacher. It is essential to find such a teacher. There is no real, longstanding progress without such a teacher.
My main teachers are the Vidydhara the Venerable Chogyam Trungpa Rinpoche and Sakong Mipham. I learned alot from Osel Tendzin. I was graced to know His Holiness Dilgo Khyentse and His Holiness Karmapa XVI. I have been greatly influenced by the writings of Tulku Urgyen, Longchenpa, Padmasambhava, Mipham the Great, and others. In a different category, I would include Will Johnson. I learned everything I know from the kindness and activity of working with the sangha (the community) also. As Trungpa, Rinpoche said, "In this business, the self made man is always suspect."
The teacher is vital in many other disciplines also. Perhaps mindfulness is a movement with lesser involvement with teachers per se but perhaps not. Sound principles tend to persist.