You're a resident in Acre (or another city in the newly established kingdom of Jerusalem) and the first crusade happens and then you're ruled by the Europeans.
If you're a Muslim are you able to continue your religion? If you were a farmer did you keep your land?
Were there any major changes in your lifestyle when the crusaders came?
If you were a Christian, did you welcome your new Christian overlords?
I'm mostly but not exclusively drawing from R. C. Smail's Crusading Warfare 1097-1193. (Specifically, chapter 3)
First of all, there was the initial violence of conquest -- the period in which homes were burned, populations massacred, etc. The Crusaders were not unique in the fact that their conquests were violent (and not just toward military targets), but I'd say it would be a rather serious oversight not to mention this. (My impression is that the Crusader conquests generally involved destruction and looting probably more severe than the norm for the Byzantines or Fatimids, but perhaps not as severe as the Seljuq Turks.)
Okay, once that's over with, the Franks are in charge. Muslims would generally have found this an unwelcome change. There are some accounts, e.g., those of Ibn Jubayr, which portray the Franks as benevolent colonial masters, but overall most Muslims preferred Muslim rule. Muslims were also forbidden to practice their faith in Jerusalem -- I am not sure whether they were allowed to practice their faith in Acre.
Armenian Christians were generally friendly toward the Crusaders, and regarded the arrival of the crusades as a good thing. This isn't to say there were never any tensions, but of the pre-existing populations of the Levant, crusaders probably had the best relations with the Armenian Christians.
Arab Christians were in a somewhat ambiguous position. They shared religion (roughly speaking) with the Crusaders, but had ties of language and ethnicity with the Arab Muslims. The crusaders did try to colonize Jersulem to some extent with Arab Christians, but they were not as consistent allies of the crusaders as the Armenians.
Unfortunately, I can't really answer your question about whether agricultural land tenure patterns changed much, because I don't know much about how land ownership patterns were in the Levant under the Seljuqs or Fatimids. Certainly, after Crusader conquest, it would have been rare for farmers to own their own land, especially since Frankish law conflated ideas of ownership and jurisdiction, so possession of land tended to go to those with political power. I don't know to what extent that was true before the crusades, though.
I can't contribute much to this topic, but I have a couple of friends who are writing dissertations on the topic. I can say that there were tensions between local Christian populations and many did not necessarily welcome the Crusaders who they feared would expose them to Muslim reprisals at some point.
The answers to all your questions can probably be found in the book Frankish Rural Settlement in the Latin Kingdom of Jerusalem by Ellenblum. From what I understand, his work on the Kingdom of Jerusalem outside of the cities is really, really well received. http://www.worldcat.org/title/frankish-rural-settlement-in-the-latin-kingdom-of-jerusalem/oclc/49414772.