Everything you said could've been handled fully with the merit based scaling quest. It could be done without increasing the level caps or creating new gear/items to stuff our already overfilled mog safe. Not only that but each job could be independently upgraded allowing people MASSIVE amounts of growth that sticks with them.
Even neat side grades that unlock traits on other jobs. Say you have RDM leveled you can unlock magic accuracy bonus. Almost as much as getting all characters to level 99 with limit breakers. Instead of limits breaker quest a new merit breaker quest for each job would unlock.
This would empower the characters by not creating a situation where you MUST constantly upgrade gear to grow. Something most people hate. There is already to much crap in out mog safe.
It's simple PUT SCALING IN THE MERIT OPTIONS.