Well, good to see some opinions. I'm not sure why 5 people said "No" though...
Maybe is because they (and I) think that the change must come from the game and not from the user. At least thats my opinion.
Nah. I kind of like the "jerkish" rivals, it makes them so much more satisfying to beat down. Hahaha.
Though an actual female rival would be very nice - someone who doesn't give up their trainer careers, just because of some silly contests, or something like that.