Re: Arabs. The editor points out that this is a mistake of the POV character. I'm assuming this Sara is an American or something, but gosh... there are tons of Americans who would assume Turkish people are Arabs, and so if that's the character's mistake it is a sensible thing to include.

Well, yeah, except that it's the wrong ethnicity, wrong language, wrong *language family*, and even wrong script.

Having one guy in Turkey wearing a turban is a lot different from having them all do it.

There's a difference between, say, a Sikh turban, the small turban some imams or those who claim descendance from Mohammed wear, and so on. But it doesn't matter, because the traditional Turkish headgear between the 1800s and 1925 was the fez, and nowadays the old-man hat of choice is the hacı takkesi. It's like having a cowboy character with a bowler or a Tyrolese hat.

Not that Turks dress that exotically, anyway.

The editor there is taking a professional tone. What, should he apologize for not being Turkish while attempting to (politely) address her concerns?

Well, apologising for glaring mistakes in the setting and shoddy research work would be nice, yes.

but I also am not sensing any kind of level of real expertise on her part, just the kind of superficial knowledge of Turkey one might have from a little learning and Googling.

That's exactly what makes the mistakes worse. It's the kind of stupidity that could have been avoided if they spent five minutes googling.