6) As a U21 coach, I have noticed that players 14 JS and 8 PA all else equal get better game ratings than players with 8 JS and 14 PA. That may or may not mean much, but I think it is some justification for those managers who tend to emphasize training primaries over passing especially early on.
Good post, considering point 6, I do think that this is logical. Passing is a skill which can 'set players free', it creates better chances. But if the receiver of the pass is a bad shooter, passing is of less use, than vice versa. Simply because there are other methods of creating chances, for instance, driving is one of them.