Slack san, well done! You commented on many things that I had noticed, and answered some questions that I had as well. All in a well written, fact based essay.
1) I remember thinking how cool gokkies and 4th generation were, and downer fans were going on and on about how without Miss x or Miss b, etc. the group was sunk, and that these newbies were ruining a once great group.
2) I saw a lot of 30+ guys at a fan event, but as you mentioned in your article, at the event that I attended, I also saw Moms with their young daughters, high school aged girls, young couples with a baby or two, high school and university aged boys (C-ute were a highly popular group that day with that demographic).....a good mix of fans across the board
3) I always supected that MM, in the last few years, was a lot like the Greatful Dead..................record and album sales fine, but live shows are the real story- with all the other Morning Musume Heads in attendance is a traveling circus, where the town follows the circus.