Yeah, this is exactly my dilemma, I mean there is so much diversity, but I can't judge how politically strong each of these groups was at the time. Was a common Arab consciousness strong enough to give a unified state a chance? Or was tribal fragmentation inevitable? And of course what are the chances that the Maronites, Alawites, Jews etc. can found their own viable states without foreign interference? I guess the Jews have a decent chance, they basically did it alone, but what about the extremely diverse Lebanon?
I know this is quite a lot, but any ideas are welcome.
As far as I've read, the Arabs at this time are still almost entirely tribal. Arab nationalism was basically born with Faisal, and introduced to the region of Syria only at the very end of WWI, and I think only really made it to Iraq in the 40s. Faisal was famously welcomed with open arms when he rode into Damascus, but I have to wonder to what extent that was indicative of the local population; and also, recall that Damascus was quite an advanced city, culturally speaking (though so was Baghdad).
That said, from what I've read, a lot of the violence in Palestine in the 20s was almost entirely tribal, rising to become a general "anti-other" sentiment only in the 30s (and of course the Palestinians lost their tribal identity and formed a national one relatively quickly after they were expelled, but shared suffering and the breakdown of preexisting society seems like it would speed that sort of thing along). Libya, even today, it still very tribal; Jordan is pretty tribal as well. Syria, Egypt, and Iraq (those states that were socialist and pan-Arabist, plus more urban) less so. Some sort of Arab nationalism could easily develop among the educated urban classes, and perhaps even trickle down to the peasants eventually (and in the mean time, the peasants won't mind nationalist Arab leaders more than they did imperialist Turkish ones). If the nationalists are smart and patient, first integrating the cities, and then slowly extending their true control into the hinterlands, they could easily knit together a nationalist state within a generation or two - or, if they overextend, it could all fall apart. And even a non-tribal government won't necessarily be stable.
As for smaller groups founding their own states without outside interference...it depends on what you mean by state. The Druze, Alawites, and Kurds under the Ottomans enjoyed, more or less, several hundred years of benign neglect. Unless the rich cities of Damascus, Baghdad, and Beirut, the Ottoman tax collectors and recruiting men never much bothered to venture in the poor, rugged mountains full of people just itching to kill outsiders. If left to their own devices, they'd probably stay as loose tribal associations until some external stimulus provoked them into unification (say an invasion by the Sunni state in Syria). They probably won't survive such an invasion without outside help due to low organization, but if the statist Arabs are disorganized enough (which, frankly, they very well might be), our hardy mountain tribes may well band together into a tribal federation that becomes more like a state every passing month. The Maronites of Beirut and Mount Lebanon are already protected by Europe per an international treaty passed in 1860. Again, if they're pushed by an external threat, they might well bind together (though the French are almost certain to get involved - they really loved them their Arab Catholics).
The Jews are, of course, something of a wildcard. The extent to which they received external aid is highly disputed (or at least, external aid from a government actor - that the world Jewry supported the Zionists to a high degree is incontrovertible - well, except for the Bundists

). While the Jews have a small, relatively dispersed population, they also have technology, organization, and motivation fairly unmatched by their Arab neighbors (a friend of mine, an IDF officer with a Master's in Middle East studies, told me once: "the reason that we won in 1948 was because, in general, the Arabs had warriors while the Jews had soldiers"). In 1948, small groups of Jews were able to use advanced tactics and support fire to hold or route Arab forces many times their size (one notable example: the battle of Yad Mordechai next to the Gaza Strip, where 130 Jews, of which only 20 were trained soldiers, held off over 2000 Egyptian infantry with armor and artillery support for 4 days). Such a state does completely lack strategic depth, though, and could easily be crushed by a sufficiently competent enemy if attacked before reaching a certain level of population (though the Zionists, likely with universal militia training for both genders and possibly contemporary European weaponry, will probably be able to punch far above their weight).
The Shiite Arabs in Iraq are very tribal still at this point (hell, they're quite tribal even today), and it'll be difficult to gather them into pan-Arabism, which often had something of a Sunni emphasis even when allegedly secular. I can't see them organizing their own state, but in the absence of British control of Iraq, I could easily see them getting absorbed into Iran.
The Shiites in Lebanon...also very tribal and disorganized. But then, so are the Sunnis. The mountainous terrain and relative diversity of the region mean it has always been pretty decentralized.
And the Bedouins, of course, are the kings of tribalism.