Hi Obsidian,
This is a most excellent question, and the kind of thinking that separates cook book astrology from the real deal. Trying to understand how and why something manifests in a chart, the underlying mechanisms, and then the practical results.
In Karmic/Spiritual Astrology the Nodes are of great significance, as they speak to soul intention and purpose in this life. In more classic astrology, the Nodes are only recently being seen as having any import, but in general the Nodes tend to be ignored by most astrologers.
In my work, Karmic/Spiritual Astrology, the Nodes are very important. So bear with me as I walk through the pertinent facts.
The Nodes are the intersection of the Moon’s path and the Sun’s path across the sky. So the Nodes are closely related to the Sun and the Moon which are major karmic, spiritual signposts.
The Sun is seen as potential energy to be developed in the current lifetime. It is what the soul is hoping to be, what the soul must be in this lifetime. The soul has come into this incarnation enveloped in the Sun sign energy, it order to learn as much as possible about that sign, good and bad.
The Moon represents deeply entrenched, unconscious feelings and patterns of behavior. It is instinctual, primal, holding karmic past life information for each soul. It is what the soul has been in the past, all that has gone before.
The Nodes then represent highly concentrated specific pockets of energy, the intersection of past (Moon) and present (Sun) spiritual energy, combining the past and present towards a focused soul purpose.
The NN represents the soul intention, the purpose and goals of the current lifetime. The SN represents the past, or deeply entrenched patterns and feelings. There is a polarity that must be unified, the opposites must not tear apart the soul, but must be integrated for the purpose of growth. It is helpful to see the Nodes as an axis.
The North Node represents new energy, potential, possibilities existing in the chart. It is thought that this is energy that must be grown into, we are not immediately living in North Node energy. We tend to be more deeply entrenched in South Node energy.
The NN energy will create pathways that lead to soul growth, and could impact jobs, finances, etc. And yes losses or gains could all make the soul move towards to soul intention. There are paths of energy that move the soul toward growth which may not be apparent at the time.
A older person who feels aligned with the NN soul purpose could look back on his or her life and see that adversity as well as good fortune all seem to have moved them towards the NN.
In terms of planetary aspects, I would say that both the Sun and Moon aspects are somewhat more important than the other planets. When the SN is in the same sign as the Sun, or the NN is in the same sign as the Moon, or the Sun and Moon are in the same sign, it tells us that the soul has been working on the sign energy for many past lives and it is now time to work on the energy in a more constructive way and to focus on the positive sign energy. When the Sun conjuncts the NN, it means that there is an urgent need in this life to work on positive sign development. Planets conjunct the SN tend to pull us back into old patterns and may feel like powerful sub-personalities.
A reversed nodal axis is also important, this is when the signs of the nodes fall in the opposite house to its natural placement. For example a 12h Virgo NN opposing a 6h Pisces SN. This is showing us that the sign energies have been worked on a great deal in the past, and there will need to be a deeper integration and final resolution of the energies in this lifetime.
Julia