” , but we claim that we are unchanged.”
Who claims that?
So much has changed We don’t have a Beis hamikdash a king, not too mention countless modern inventions like printing presses, cars etc. Why are all those changes “ok” but changing the script, THAT is where you draw the line?
“What makes us different than the italians, iranians, egyptians and so on ”
That we keep the Torah.
” what is the proof that we have not changed”
We have!
I’m not dismissing your questions.
Just pointing out that your angst over the sudden realization that not everything we do/practice etc is EXACTLY the same is a bit misplaced