Phil,
good thread, with good posts.
One thing I think fairway bunkers do is "set the tone" for the course, and for the round. In the case of a very good player, the effect might be mostly psychological, i.e. he/she won't find themselves in the bunkers very much, but the way the bunkers are placed and their frequency of use sends a message to the golfer that has an influence/impact: "this is a penal course, and a stern test, so you'd better have your A game", or, "this is a strategic course, with many available options, but you have to use your imagination, and make your own choices".
For the rest of us, they may be mostly directional, or "anti-directional," and whatever their pyschological effect it pales in comparison to the...err... actual, stroke-costing real ones.
Peter