you hit the nail on the head, however note that even in Saudi Arabia there is a lot of discontent — the Shias, Ismailis, Boras etc. are discriminated against heavily, their holy shrines have been bulldozed. And amongst the Sunnis, there are a lot of poor, because the wealth of that kingdom is treated as the personal wealth of the Saudi royal family (3000 princes and counting). Furthermore, the various arab tribes regard the house of SAud as usurpers from the Nejd region who went on to conquer Hejaz and the rest of the Arabian plateau. Civil unrest is highly likely — in fact it was happening until the British idiot, Lawrence of Arabia helped out before WWI
I probably should have remebered there is still religious tension, I mean, a Mid East or Islamic nation without religious tension is like Never Never Land. And of course there ar emany very angry discontent people in Saudi Arabia, in Mid East nations there are always people who want to taje down and kill the current leaders and force themsevles into power. That is why there were turmoils and assasinations in Saudi Arabia, which I am aware of. In nations that rife with warring religions, sects of Islam, tribes, clans and families, discontent and murders and riots and rebellions and assinations are inevitable byproducts.
But having oil reserves vs not having oil reserves will still make huge differences I think. What makes it worse for people in oilless arab nations like Egypt or Jordan is the fact that America and a lot of other nations give the regimes support that is often seen as pointless. Although it is inane and dangerous and senseless that we do business with Saudis for our oil, in some ways our support of Egyptian and Jordanian regimes is actually far more shameful. Often the only thing we get in return for that is pledges to fight terorrism that originated in their nations, and they only follow said pledges when an actual terror attack does happen, like the 9-11 where numerous hijackers were fo course Egyptian. Often, the support we give Egypt and Jordan is completely unconditional, which magnifies the fury of the people. We often have to because the only other options are worse ones (Muslim Brotherhood) but the way we do it causes magnified tension as well.