I looked up the movie on imdb, and it appears to be something that I, as a parent, would not feel it exactly appropriate for kids, from the movie description. However, I haven't seen it myself, so I can't really say. But I wouldn't rent the movie and watch it in front of my kids. It has a pg-13 rating, not an R rating, so it can't be *that* bad though... Airlines can't be expected to show only G rated movies on flights, so some amount of "deal with it" factor is going to have to be accepted on the parents' part.
The sound on airplane movies doesn't go over the PA system, so without headphones the kids won't hear it, and if an iPad/books/etc are brought along for the kid, their attention could be focused on those things instead of the movie screens high up on the airplane ceiling. I'm not familiar enough with airbus systems to know if it is or isn't possible to raise one screen without raising them all. They may be tied together, and not able to be raised individually.
And yes, this is totally one of those "I want to hear the whole story" kinds of cases. There's no way what we're hearing/reading here is the whole story.