There is no word I'm aware of that quantitatively and qualitatively identifies the "source of all energy". This is purely because nothing is known of the concept, except that the laws of energy determine it must exist. Hence no word for it . . . unless I'm behind on the subject?
The word "deity" has many applications and definitions depending on context . . . so I take your point that the word may not convey accurately the thought being discussed. It seems that many applications of the word are in reference to past and existing concepts of God and their being objects of veneration or worship.
This is not the context in which I used the word. The point being made is that it can be concluded scientifcally, that the energy manifesting itself as the physical world . . . must have a source . . . nothing more.
The "argument" is this . . . any conclusions beyond that are conjecture and/or speculation and therefore unscientific. This fact is born out by the fact that to date, the existence of a "god" cannot be proved or disproved scientifically. That being the case, the true scientist will leave the door open to either possibilty, regardless of his/her personal conjecture, speculation or personal belief.
To adhere to either theism or atheism . . . is not scientific. Each is a declaration of belief for which the supporting evidence is by no means conclusive . . . that's all.
It is often the inclination of the entrenched atheist to present thier argument as being more scientific . . . when in terms of known scientific fact, is simply not true . . . the physical world and what is currently known as to it's nature . . . does not preclude the existence of "god" in a general unfettered sense.
It's not that easy to divest oneself of previous convictions and prejudices . . . nor is it unusual to go looking for "the science" to support a strongly held belief. We are not as generous as we could be, in allowing for the unknown.
As for me . . . I am neither theist or atheist . . . because I have very little scientific proof of either. Well short of where I could declare either an "absolute".
In response to your conclusion, I could say that God's habitat is gradually being uncovered by advancing science. It is only erroneous concepts that are being eroded.