@ anonymous jew
“our alphabet uses Aramaic letters”
False. There is no evidence that Ksav Ashuri was used by gentiles in Aram (or anywhere else). The Gemara gives a different reason for the name. So this statement is not supported by archeological or Talmudic evidence.
“They were adopted during Galus Bavel.”
What you mean to say is adopted by Ezrah at the end of Galus Bavel
There is a 3 way disagreement among the Tannaim regarding Ksav Ashuri. The above statement may be true according to R’ Yossi, however
1) The Geonim who appear to understand R’ Yossi that way write that the Halacha is not like him
2) The Ritva and Ridbaz write that even R Yossi agrees that Ksav Ashuri goes back to the time of Matan Torah
Central to the whole discussion is a Yerushalmi that states the the Ayin in the Luchos was supported miraculously. The Bavli says it was the Samach and the Ritva disregards this Yerushalmi. The Ridbaz distinguished between the 1st and 2nd Luchos. The Yaevitz learns that even the Yerushalmi is using the familiar Ksav as a mashal to explain the nes and isn’t meant historically.
Prior to that, we used Paleo-Hebrew, which is shaped totally different.
This is TBI (true but irrelevant). We used Yiddish in Europe, and all the seforim where written in Lashon Kadosh
“The Samaritans, who copied every we did, still write their ( tref ) sifrai torah in Paleo-hebrew which leads me to believe we did too before the first churban.”
It might be that during the 1st Beis HaMikdash writing Sifrai Torah in Ksav Ivri (Paleo Hebrew) was permitted. This has no bearing on the antiquity of Ksav Ashuri.
“Paleo-hebrew was still in use 2000 years ago as it appears on coins minted by Bar Cochba…”
Once again, TBI