Vog Mur is literally on the map of MIddle Earth Terry did for MERP.
That, I did not know. Today I Learned!
Being an atheist (or I guess agnostic) myself, I rather like the way Terry wrote gods. There does seem to be a bit of tension there between the absolute Good and Evil we see in some of the spell lists, and the more relativistic cosmology Terry espoused in his world-building.
I did not *know* it either, but there were a number of hints dropped on both sides of the product line (some names, and the way some parts of Vog Mur are described. On the MERP side, I think Court of Ardor and Shadow in the South are where the similarities are the strongest).
About Kulthean Gods - I think Terry never deviated from his idea that the "gods" or Orhan and Charon were not true gods in the way we see divinities nowadays (i.e. near-omniscient and near-omnipotent, because of the prevalence of monotheistic faiths). They are basically very powerful, intrinsically noncorporeal extraplanar entities. And the difference between a true god and a very powerful alien is slim in the eye of a mere mortal. Thus, "gods". Even the 'local gods' are powerful spirits. Kulthea is fundamentally a world without true gods, without absolute power... until the Unlife enters the picture.
This view I have of the Shadow World cosmology shaped the way I see magic (everything comes from manipulation of the Essaence) and the relation between the Orhan 'gods' and their followers (casters from the realm of channeling use gods as mental icons to manipulate the Essaence - basically, the channeling realm is a mental representation that helps the practitioner with the task of spellcasting by associating mental symbols - 'gods' - with the sequence of mental actions). In other words, channelers use a crutch to perform magic - but a crutch that allows them to bypass some of the intrinsic difficulty of casting spells. Gods do not control the magic the faithful cast in their name, but they *can* be interested in some people in particular, and either enhance their abilities or hinder or block them.
Now about Good and Evil. I think the 'evil' lists are awfully badly named. Evil is intrinsically cultural rather than absolute. And 'Evil' magic is still magic, and still powered by the Essaence. On the other hand, if magic is Essaence shaped by will and intent, then you can say that 'Evil' magic is shaped by sinister, selfish, or sadistic intent (negative personality traits)... but it could also be shaped by pain, or the desire for retribution or vengeance at any cost, which are negative as well but much more difficult to ascribe morally. Basically, if magic is an exercise in applied willpower, then evil magic is an exercise in fueling willpower with a negative emotion (pride, rage, pain, greed) for increased capability at the cost of having effects tainted by that emotion. It is only "evil" if those emotions are considered evil, but it is tainted - and you could easily imagine 'good' magic being similarly powered and tainted by very positive emotions such as love, compassion, joy or similar.
And about the Unlife - which, according to the scriptures, is totally different from the Essaence, and utterly alien in origin. I've always thought of the Unlife as a negation of creation. Not the act of destruction, but the resulting state - quietness, peace, stagnation, stillness, the indifference of absolute nothingness. There is power in that, and it is a seductive song for the tormented - the lure of peace where the Essaence promises change (because life is change). Lorgalis, when arguing that the Unlife was the enemy of death, was not explicitly lying but was doing an Obi-Wan on Elor: Unlife is the antithesis of everything that changes, even of living immortals. Its ideal state is total nothingness - and such thing cannot be understood by living beings. However, the song of peace, and the lure of being able to destroy, are tempting for those who seek power beyond what the Essaence can provide (because the power of Essaence is limited by one's willpower).
That is how I make sense of it all - no true gods, an energy of change that is shaped by will, taint from emotions, and a seductive lure of unending peace through nothingness. And in the end, the universe dies (the theory of universe death by cold is the closest thing to the Unlife I can imagine).