To expect the front seats to be the goal keepers for everybody elses mistakes is to expect far too much.
I disagree. To me ( on a daily basis) it seems that is the primary role.
The crew have to accept that the people within all departments are professionals doing their tasks in a professional manner.
Again I disagree. Maybe accepting that most within all departments will do their jobs in a professional manner I could agree with. The crew have to accept, and be comfortable with, the fact that some people will not do their jobs in a proffessional manner and as a result during their career the crew will see rags left in undercarriage uplocks, cowlings left unlatched, out of date data bases loaded, correct data bases loaded with waypoint errors, poorly designed stars and approaches, ATC clearances that create traffic conflicts, banned dangerous goods loaded for flight, incorrect fuel loads uplifted, important ground handling procedures not followed etc etc.
The role of the flight crew ( among other things) is to recognise these things and deal with them in an appropriate manner, this is happening all day every day all around the world and is why Airlines won't give jet commands to people who have 500 hours. Most 19 year olds could quickly learn the stick and rudder stuff, it is this fandangled airmanship thing that can't be taught at university.