That it was written in Greek isn't evidence against Aksumite authorship or for Greek authorship. There are multiple examples of Aksumite kings using Greek for monumental inscriptions, including the Sembruthes inscription and Ezana's inscriptions. As I'm sure you know, Greek was as a prestige language, especially for documents intended for international audiences. The fact that it was written in Greek actually supports its diplomatic and international significance for an Aksumite king establishing regional dominance.
Irrelevant. We agree that the events described are prior to Cosmas' lifetime. However, you bizarrely want to push it back to the 3rd century BC without evidence where there is nothing in the
pre-Aksumite material record thus far that supports any kind of Greek military presence in the region though there is plenty of Greek influences meditated through trade.
We know Aksumites and even Adulites like Zoscales were Hellenized. This isn't a surprise. Even Kings like Ezana in the 4th century reference Greek deities in his Greek inscriptions.
I'm glad you shared that map as it clearly illustrates campaigns designed to gain control of the maritime and overland trade routes in the Red Sea and its hinterlands and securing peace and order along these trade routes. Interestingly, the map campaigns near but not really through Aksum itself - perfectly logical if the author were the king of Aksum.
The King establishing headquarters at Adulis upon returning from campaigns in South Arabia to suppress revolts in Africa aligns perfectly with Aksumite strategic interests in the 3rd century and even also references from the likes of Mani which seem to corroborate Aksumite expanding influence during this period - also attested by the South Arabian inscriptions mentioned in my previous post.
By the way, the goal of controlling the route to Egypt also corresponds perfectly with the documented Blemmyes/BeJa incursions into
Roman Upper Egypt and Lower Nubia starting in the mid-3rd century CE, which would have been driven by Aksumite expansion from the south during this period.
Even more damning for your Ptolemy theory is when the inscription tells us:
"Having subdued the Atalmo, the Bega, and with them all the Taggaite peoples who occupy territories leading to the frontiers of Egypt, I made travel overland feasible along the route
leading from the territories of my kingdom as far as Egypt."
If this were Ptolemy, wouldn't Egypt itself be his territory? The author's kingdom was clearly a kingdom to the south that was establishing a secure route toward Egypt - exactly matching Aksum's position.