Is 'darkness upon' in Genesis 1:2 cosmic, rather than merely terrestrial, despite that the central subject (Earth) and Biblical Hebrew grammar (ex:Luke 23:44, Exodus 14:20, Deuteronomy 4:11, Joshua 24:7, 2Samuel 22:12, Job 3:5, Job 17:12, Job 22:11, Job 38:9) suggests the latter?
The Hebrew word you are referring to is, in Masoretic notation, חֹ֫שֶׁךְ - ḥōšěḵ.* The Septuagint reading is σκοτος - skotos (also the word used in Luke 23:44, which you cite).
Strictly speaking, it is not the earth (אֶ֫רֶץ - ʾěrěṣ) but rather the deep (תְּהוֹם - tehôm) that is covered by the darkness. The understanding here was that the waters of the deep completely covered the earth, which were themselves completely covered by the darkness.
You state in the question that the verses you cite (Luke excepted perhaps, since it is Greek) all refer specifically terrestrial darkness, and not some cosmic or abstract darkness. While this seems true in those specific cases (except for Joshua 24:7, which uses a different Hebrew word), it is not true in general. Examples of other verses using ḥōšěḵ:
1 Samuel 2:9
He will keep the feet of his saints, And the wicked shall be silent in darkness; For by strength shall no man prevail.
2 Samuel 22:29
For thou art my lamp, O LORD: And the LORD will lighten my darkness.
Woe unto them that call evil good, and good evil; That put darkness for light, and light for darkness; That put bitter for sweet, and sweet for bitter!
Such as sit in darkness and in the shadow of death, Being bound in affliction and iron
The understanding in Genesis 1:2 was that the earth was still without form and void. The darkness surrounding the face of the deep was utter primordial darkness. A note in the Oxford Jewish Study Bible (2nd ed.) explains:
This clause describes things just before the process of creation began. To modern people, the opposite of the created order is “nothing,” that is, a vacuum. To the ancients, the opposite of the created order was something much worse than “nothing.” It was an active, malevolent force we can best term “chaos.” In this verse, chaos is envisioned as a dark, undifferentiated mass of water. In 1.9, God creates the dry land (and the seas, which can exist only when water is bounded by dry land). But in 1.1– 2.3, water itself and darkness, too, are primordial (contrast Isa. 45.7).
* Transliterations taken from Swanson, Dictionary of Biblical Languages with Semantic Domains : Hebrew (1997)
….and darkness was upon the face of the deep (the abyss of man’s heart).
For me, the “darkness” is cosmic in the sense that this verse is not literal but a metaphor for the darkened heart (deep/abyss) of mankind void of the heavenly (cosmic?) knowledge of God. The earth became without form (without His righteousness) and void (empty of His knowledge) as mankind has turned away from God and follows its own paths that man considers as "wise".
Genesis 1:2 KJV (2) And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
God made man upright but they have sought out many “inventions”….contrivances. Man has departed from God's Way and gone after his own ways.
Ecclesiastes 7:29 KJV (29) Lo, this only have I found, that God hath made man upright; but they have sought out many inventions.
The earth became without form…without righteousness. All have gone out of the Way of righteousness and all have together become unprofitable.
Romans 3:10-12 KJV (10) As it is written, There is none righteous, no, not one:
The earth became without form….without righteousness (as none does good, not one) and void of understanding (there is none that understands).
(11) There is none that understandeth, there is none that seeketh after God. (12) They are all gone out of the way, they are together become unprofitable; there is none that doeth good, no, not one.
Becoming vain in their imaginations…discussions….thoughts, mankind (yet professing himself as "wise") has had his collective foolish heart darkened (darkness was upon the deep).
Romans 1:19-22 KJV (19) Because that which may be known of God is manifest in them; for God hath shewed it unto them. (20) For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse: (21) Because that, when they knew God, they glorified him not as God, neither were thankful; but became vain in their imaginations, and their foolish heart was darkened. (22) Professing themselves to be wise, they became fools,
The “deep” is the heart of man. Counsel in the heart of man is like “deep water.”
Proverbs 20:5 KJV (5) Counsel in the heart of man is like deep water; but a man of understanding will draw it out.
The inward part of man and the heart are deep.
*Psalms 64:6 They search out perverse things, 'We perfected a searching search,' And the **inward part of man, and the heart are deep*
The words of a man’s heart are as deep waters.
Proverbs 18:4 KJV (4) The words of a man's mouth are as deep waters, and the wellspring of wisdom as a flowing brook.
Those things which proceed out of the mouth come forth from the heart….from the deep…from the inward abyss of man’s thoughts and reasoning.
Matthew 15:18-20 KJV (18) But those things which proceed out of the mouth come forth from the heart; and they defile the man. (19) For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies: (20) These are the things which defile a man: but to eat with unwashen hands defileth not a man.
Mankind needs "recreated" in a sense...reconciled back to God. Mankind in the darkness of its own heart needs to hear the true, sincere Word of God as men speak His words as moved by the Spirit (the Spirit of God moved upon the waters).
Let there be light….and that light dawns and arises in the once darkened heart of man. The “evening and the morning”: the light shines in a “dark place” (the evening) as the day dawns and the morning star (the morning) arises in the heart.
2 Peter 1:19-21 KJV (19) We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: (20) Knowing this first, that no prophecy of the scripture is of any private interpretation. (21) For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.
2 Corinthians 4:6 KJV (6) For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ.
The light shines and progresses until the darkness fades and is no more within the heart….as the light of 7 days.
Proverbs 4:18 KJV (18) But the path of the just is as the shining light, that shineth more and more unto the perfect day.
Thanks for reading and considering.