As an excersize, you can plot a par 4 golf hole at a short, medium and long on graph paper. Put in a blob of a green at whatever angle you choose - say 10 degrees angled to the right. If you presume that the risk taken is to hit just inside the fw edge on the right for the angle in, you can find out pretty quickly what width is necessary to create that challenge. Generally, width required to create risk widens with length of hole and angle of the green.
But is width for widths sake any good?
Any width further right of that perfect approach angle for the opening is just making the golfer hit to the middle (or mid right) of the fw, with less penalty for missing right, (or left) and reduces risk, and thus strategy.
"Too much width" left certainly has some value in highlighting the advantage of flirting with the rough on the right, but at some point, the advantage or avoiding rough off the tee by playing safe probably outweighs the advantage aiming for the right edge. You are assured of a lie in the fw while playing safe and may be able to bomb tee shot to gain advantage of a shorter iron shot at harder angle. Of course, that is an option!
Since most golfers can regularly hit a fw about 35 to 40 yards wide about 2/3 of the time, anything more than 17-20 yards left of the centerline might qualify as "too much width." I think there is some practical limit as to how wide the fw on the safe side should be to create strategy, and about 40-45 yards probably wide enough when considering strategy, speed of play, mowing costs, etc.
A couple of other thoughts -
I agree rough only needs to be high enough to cause flyers....
From experience, and relating to TD's story, I find that the turf corridor (whether rough or fw) needs to be about 80 yards wide. At 70 yards wide (sometimes typical because that is what 3 rows of sprinklers cover) I find that on every hole, one of the 10 handicappers TD mentions will be in the adjacent woods or native grass. I doubt there would be many lost balls at all in the same foursome at 90 yard wide turf corridors.
I am not all that enamored with center bunkers. Despite a flowing mowing pattern, in essense you need to have an adequate area on both sides of that bunker making it a cosmetically disguised second fw, with all the problems associated with that - using more space and resources for what usually gets exposed as a less favorable route, although that is not even a given, esp. on windy sites.