And concerning the attackers from islands: The Sea Peoples serve well, here.
And others, too.
Look, again I do not want to claim anything, but to claim only one thing:
LET US SEARCH! For heavens sake, do not interrupt a search before you know where it will lead to.
You yourself defined criteria for this search in your posting above, now let us follow this path!
Maybe, maybe not. According to Karl Kerenyi the Pillars of Hercules once stood in the direct south-west of Greece.
But this is not the question, because: In an old (very old) Egyptian text surely nothing was said about the Pillars.
Something was written there which made the Saitic priest to immediately think of Gibraltar.
I take this as an admission on your part that you didn't understand a thing I said.
I see no purpose in searching for something the physical sciences have already shown didn't exist. And since whatever may have inspired the story doesn't make it Atlantis, it has no bearing on the real world.
This is unevidenced speculation on your part and nothing more. There's no textual evidence to suggest any of this was ever true.