I do not work in an airline myself and I'm always curious about this. I apologize in advance if my questions seem naive.
From reading the many posts on this forum, it seems to me that crews (both flight and cabin) are not scheduled to work with a consistent "team" of people all the time. It seems that the cabin crews are working with different individuals and the flight crews are flying with different people everyday (if not every flight). I would've thought that there are great benefits to schedule a whole set of crew to work together for some period together so they will get to know one another better and be able to serve the customer better.
Also, how are crews evaluated by their supervisors? Do the pursers each day file a report of how each person did that day? Are promotions basically given based on seniority?