I think Jewel is right about the energy not necessarily being good --- too much of any one energy in a person's life is not good (could you imagine if you were so full of Transfiguration that your friends and family didn't even recognize you from day to day? Or so full of Courage that you forget to think things through before charging headlong into any situation?)
To me, the Singers are about journey and balance in our lives. We move through the cycle over and over again throughout our lives, begining with Solus: we put one foot into the etherworld, like putting our faith in higher powers but keeping our determination in our own hands. We are the masters of our own actions, but we are not islands unto ourselves. We incorporate the Singer of the Chalice into our everyday thoughts and actions, bringing creativity and imagination to everything we do, and eventually we are Transfigured, in some way or another, by our consious effort to bring the energies into our lives. Sometimes, the transformation can be so dramatic that we must pause for a while and Heal ourselves from the inside out, recovering from the effort it takes to undergo such a change, but our journey is not yet over.
Once we have learned to incoporate these energies into our phsyical lives, we undergo a passage by trial, the Initiation into the higher spiritual realm, whatever you might call it, whatever your beliefs say this means: perhaps it is forcing yourself to follow a specific doctirne (keeping Kosher, abiding by the pillars of Islam, the commandments of the Christian-Judeo tradition, the mantras of Hinduism, etc etc) Maybe it is simply taking up the search to find something that speaks to you, on a personal level, to bring you closer to God/Goddess/Unity/Nirvana/Whatever you want to call it. This isn't always easy, especially in these days, when so much socially acceptable behaviour is not acceptable to your chosen path. It takes Courage to stick with it. It takes Intuition to know that you are on the path that is right for you, for this point in your life, and it takes a sense of Connection to make sure you know you are not in this alone. We must learn to bring all of these energies into our lives, and balance them so that no one overwhelmes any other. If you have plenty of Intuition telling you 'try something new' but no Courage to do it... well, that won't get you very far at all, will it?
Then we come to She of the Cruach and He of the Fiery Sword, the two most overpowering energies within us. It is easy to let one be more influencial than the other, especially if you have a classically Feminine or classically Masculine personality, but at this point in our journey we must recognize both of these energies and, though we may not be able to balance both within ourselves, we must recognize the aspects of ourselves that are controlled by these two energies, and we must be sure to acknowledge their balance within the greater world.
When we have come as far as we can for now, we pass through the Gate, and we experience Extasis (Nirvana, Divine Understanding/Vision, Holy Communion, whatever) and we taste Unity, and when we return again to the begining, we are all the more eager to go through the whole journey again.
At least, that's as best as I can explain my thoughts on this right now. I don't know if any of that made any sense to anyone (I'm not really convinced it made sense to me lol) but *shrug* it's as best I can do for the time being.
And, individually, of course, the Singers are wonderfully complex energies that have truely important messages for us.