If our object of causation isn't a personal entity, then it lacks the bare minimum traits necessary to call it a deity. Then your argument isn't establishing that god, as the term is normally understood and used in actual cosmological arguments, exists. You might as well as define the universe as "god," point out the universe exists, then conclude a god exists. The upshot is that you've established god exists. The downside is that this isn't what people mean by the term and the same trick could be applied to anything. If I define God as a pencil, then the fact that I'm holding a pencil in my hand proves God exists. Yay!
I believe the cosmological argument results in a necessary being. The universe has been eliminated when you allowed for practical purposes the science that demonstrates it has a beginning, or is contingent. I was making the point that a necessary being - although not directly from the cosmological arguments demonstration is conceptually identical to Christian deity - it correlates with deity, it is a creator, very powerful, self-sustaining, eternal and the cause for its own existence - traits that aren't exhaustive of Christian deity's conceptualizations but consistent with. If you want to call a necessary being a mikwutum that is fine, but a necessary being isn't the downside that you describe above - it is commensurate with a theists understanding of God without being as detailed as would otherwise might be preferred.
The problem with mikwitum is precisely that it could be applied to any situation because it tailor-defines itself to have the power to bring about whatever observation it is we are seeking to explain and thus trivializes the problem. There are real life historical examples of mikwitums. Design arguments work that way. God is a mikwitum in theistic arguments, usually. And if you tailor define God to bring about lightning, volcanoes, and morality too, that doesn't help the problem. It compounds it. Even if we grant that the universe requires a metaphysical cause, which is not a point I would grant, what you need to do establish that a personal object is more likely to be the case than a nonpersonal one. Otherwise, you've done nothing to support the existence of a deity. You fall into the simple special pleading trap that early cosmological arguments do where God, and God alone, is excepted from the causal rules the argument sets up for no good reason in particular.
As a theist I find the confluence of the creation of the universe with my religious beliefs properly warranted and obtained from a creator. I understand you reject that, but I point it out because that is merely arbitrary on your part unless you also properly provide defeaters. We have no antecedent scientific or natural principles for you to override with here, they cannot help us outside of space, time and the natural universe that has been established as contingent. We are unavoidably in a metaphysical undertaking. So a made up something isn't as powerful explanatory wise as a necessary being. God provides the best or ultimate explanation because the necessary being, is uncaused, so your further attempts at explanation of God is required only of those things that are contingent - that is, those things that if they do exist, could possibly not have existed. Just as a necessary being God is both eternal and does not depend on anything for his existence. When we determine a crime we appeal to personal agents and we reach finality when with personal explanation that appeals to intentions of an agent We don't attempt to analyze in the way you are doing of a necessary being. Applying further accounts of why persons acted as they did can be pursued but it isn't necessary. My appeal to God as an intentional agent leads to a confluence not only with my own personal religious experience but the universe itself, its order, its comprehensibility to persons, that it includes the existence of personal beings that can comprehend it. The properties of the necessary being are correlated with those of the God of religion. I don't find those things trivial and the correlation isn't as tight or even existent for your mikwutun non-personal explanation.
my regards, mikwut