Michael Topper made a good point about two types meditation, one that pulls the consciousness down into the subconscious, and another that pulls the subconscious 'upward' into consciousness. The first he said was wrong and only served to lower awareness and focus, and was the type taught in mainstream books and schools. The second he said was the key to higher awareness, which basically involved keeping the conscious mind intact but allowing it ever greater access to the subconscious.
The barrier between conscious and subconscious reminds me of the sound barrier. When you go through it, your plane suffers a momentary period or extreme turbulence. Somehow, the undisciplined consciousness fails to survive this transition intact. And so we enter our subconscious dreamscape forgetting we just went to sleep, and then we wake up having forgotten most of what happened while asleep. That is, unless the conscious mind becomes stronger and more integrated with the subconscious, then there is less disintegration when crossing the barrier.
I'm reminded of an analogy concerning water droplets and the ocean. A drop of water loses form when it falls into the ocean. It may go in and come out as a drop of water, but not the same drop. On the other hand, ever see smoke rings? They can travel pretty far without disintegrating. A smoke-ring like vortex of water will retain its form even when traveling through the ocean.
So the process of strengthening and integrating your mind, basically what esoteric training is about with forming the magnetic center, would be like forming your mind into a vortex rather than a weak little drop. Actually, according to the esoteric stuff, you're creating an uplink between yourself and your Higher Self during the day, and this uplink is like an air tube between boat and diver, or like Ariadne's Thread as dreamosis mentioned, keeping you intact when diving into the subconscious. The mind can retain its form when entering the ocean of unconsciousness when it has the proper self-sustaining form (like the smoke ring). At least that's how I understand it at the moment.
As for fear, I was just reading about this in the Cosmic Awareness material twenty minutes ago. Explained it pretty well, basically that fear is useful as a survival mechanism as long as it deals with an immediate threat and heightens the success of your actions in dealing with it. For example, it quickens your reflexes, lengthens your stamina, ang heightens your strength so that you can escape or confront physical threats more effectively. But fear becomes a problem when it is persistent, then it really does no good. It can make you overreact, scatter your energies upon an array of imagined threats, and keep you from gaining the necessary awareness to find out if there's anything that needs to be dealt with. On a metaphysical level, while awareness repels danger fear actually attracts it, and not having or applying awareness but being fearful is a recipe for attracting all sorts of predation and misfortune.
Acquiring fringe knowledge is like digging for diamonds in a mine field.