the thing I would appreciate would be set skills that can be leveled up
A possible suggestion is that a new skill system be implemented, sort of similar to how set skills compared to the regular class skills.
-The new skill system will require a new currency of course, as it will not be linked to the talent points for class skills.
-The new currency needed to increase the new skills would come from events, much like mementos or justice points. Or even better, the skills would require those to be increased.