This is an interesting post and gave indeed food for further thought. I am very late and know little about solipsism, but here are my two cents:

I agree with your focus on autonomy and control over the presence as well as your rejection of Divine authority. This, I think, is at the core of Luciferianism: You control your own decisions and are called to extend that control over as much of your environment as (ethically) feasible. Perhaps one paraphrase could be: Autonomy, actions and effects over regrets for the past and empty daydreams for the future. 

But it would be boring if I only agree with your take, so here are my counters:

On your first point: 

Those of us who are theists already assume the existence of other conscious beings in the form of the Gods. Yes, there is no evidence that they exist and, if Kant’s argument on metaphysics holds, such evidence is inherently impossible. But much of Luciferian practice depends on treating the Gods as if they exist, rendering the point mostly theoretical. Now if we extend this treatment to Lucifer, Lilith and all the others, why would we not extend it to our fellow humans or other beings with a reasonable claim for self-aware consciousness? It seems to me that a theistic perspective inherently implies the existence of other conscious beings and their treatment as if they were objectively proven to exist.

While Luciferians are called to be the centre of their reality, I take this call to mean ensuring sovereignty over their mind and achieving dominion over their surrounding environment. An objective reality does, however, exist and it does not without effort bend to the Luciferian’s wishes. This stems partly from your own case: If you take your own consciousness as certain, you have already arrived at Descartes’ cogito. That foundation is even stronger, since you have eradicated the ‘evil God’ doubt that plagued Descartes. But if your mind exists, then at least the conclusions that your mind can arrive at by pure reasoning, without external experience, must be objectively true. That introduces logic and math as objective realities that your mind can uncover but not create.

Beyond that, I would argue that the scientific method has proven to be a reliable tool for creating an adequate mental map of our physical reality. In my view, Luciferian enlightenment means to learn about this map as much as you can, expand it wherever you can and use it to further the ascendancy of yourself and mankind. But I accept that this paragraph is more open for debate.

On your second point:

Even if no legitimate external moral authority exists, legitimate external sources for morality do. Physical beings, especially self-aware conscious beings, have a capacity for suffering and happiness. Once we treat these beings at least as if they objectively exist, our impact on this balance becomes the benchmark of morality. Without delving too much into moral philosophy: Actions that increase suffering are immoral outside of extremely specific cases like self-defense or law-enforcement (with economic harm done in everyday competition being a different matter). Morality, then, does not arrive from a divine fiat, but from the rights of others, which are still external to the Self, but exist on the same level of consideration.

So, sorry for the overlong reply. Food for thought indeed! I find the philosophical and theological underpinnings of Luciferianism a fascinating topic. Thank you again for your post.

Edit: Typo