Here is a précis of Runciman's bit on the demographics of Outremer, and I haven't come across any other description in detail.
Runciman says that in the KoJ there were not 1000 knights, barons etc resident and their non-combatant relatives not much more than 1000, so the entire lay upper class was about 2-3000. Antioch, Edessa and Tripoli probably had about the same in total. In the north there was some intermarriage with Greek and Armenian aristocracy but further south there was no local Christian aristocracy but there was a strain of Komnenes in the royal family bloodlines.
The sergeants settled on their lords fiefs and by 1150 were beginning to form the class of poulains, by 1180 there were about 5000 of them and they were intermarried with local Christians. Runciman considers Turcopoles were probably recruited from 'half-castes' who spoke their mother's language, so they were part Frank as well.
There were colonies of Italians in virtually every coastal city and town, but apart from Acre these were only a few hundred strong and didn't mix with their neighbours.
The majority of the population was composed of native Christians. In KoJ almost all were Orthodox and CoT had some Maronites. Further north the Christians were mainly Jacobites with large colonies of Armenians and large groups of Greek Orthodox in Antioch, Cilicia and Lattakieh.
In the 1st Crusade large numbers of Muslims emigrated, including virtually all the large landowners, but there were Muslims around Nablus. In many districts conquered later the Muslims didn't leave, this is important since much of the coast wasn't incorporated until many years later, Sigurd of Norway helped capture Sidon as late as 1110 and Tyre didn't fall until 1124. In northern Galilee the locals were Muslim and further north heretical Muslims acknowledged Frankish rule.
Runciman says that the crusade of 1101 affected the whole crusading movement. The road across Anatolia remained unsafe, even the Byzantines had to operate at the end of long and exposed communications. Instead of the thousands of useful colonists this crusade should have bought only quarrelsome and discredited leaders arrived, and Outremer had plenty of quarrelsome leaders already. Pilgrims and potential immigrants were afraid to travel by land but couldn't afford the fares to come by sea, and those who could strengthened the Italian maritime states.