*Sorry if this a necro, but I didn't want to start a new thread on the same thing.
What if Venice had gone the indirect rule route? Instead of outright annexing Morea as a colony, Venice sets up a "Despotate of Morea". The, lets say, 30 most influential families each get to send a representative to an assembly, which acts as a legeslative body and nominates a "Despot of Morea" who is then confirmed by the Venetians. Morea's relationship with Venice is regulated by a permanent treaty which gives Venice control over Morea's foreign relations and a monopoly on all of Morea's external trade. No foreigners (besides Venetians) are permitted to own large landholdings/businesses. The Despot is permitted to raise a locally recruited military, and Venice assists in training it and modernizing all of Morea's fortresses.
Thus, when 1714 roles around, Venice has almost as much control over Morea's economy as OTL...but they've built a political system that gives the local aristocracy considerably more power than the Ottomans did, and which the aristocracy thus has an interest in maintaining. Thus, instead of an army of a few thousand mercenaries, the Ottomans are met with one several times larger, made up of locals who are defending their homeland from foreign invaders, and are defending from a network of somewhat modern fortresses, including one sitting right on top of the isthmus of Corinth. This not to say that the Ottomans can't take it...but its going to be potracted and ugly. They'll have to progress fortress by fortress, facing an enemy perfectly happy to melt back into the hills and villages and conduct guerilla warfare. Thus, they're in basically the same situation that Ibrahim Pasha was when he tried to crush the Greek revolt-yes, they can conquer Morea given time, but its going to take years, will probably involve wrecking a considerable amount of it (thus reducing its value once its conquered), and at some point, the Austrians and Russians are going to look at the whole situation (which probably isn't that nice to the civilian population) and find plenty of pretexts to intervene.