While I do agree that your ideas are good, I wouldn't like to grind for Job EXP.
Sure, a lot of people have a lot of classes at R50 now but they aren't the only ones that play this game, other people still have other classes at low leves and even some of us haven't reached 50. In my point of view, that would be a good excuse for me to try leveling Lancer so I can try the Dragoon Job, so it might get players to do something once they reach 50 with one class.