El Al has no restrictions on who they sell tickets to, but I would assume an Arab's check-in interview is a little more, uh, thorough than most. Also no airside transit in Israel, so you have to obtain an Israeli visa for the nationalities that require it.
KSA has direct airside transit, so having/not having a visa would be irrelevant.
IIRC, EK does not offer a Kosher meal, but QR and the Abu-Dhabi-based-airline-that-shall-not-be-named both do. I assume they bring it in from some European station if it's a hub-origin flight.
The UAE doesn't allow Israeli citizens to enter (although I believe they did before the Mossad incident a few years ago), but there are no restrictions on transits. Supposedly if you have an Israeli stamp, you need to be pre-cleared by CID regardless of nationality, but I haven't heard of that happening recently.