Character development could be done the same way as the advanced class quests method, where you obtain a skill or AF from each quest. While each quest unfolds the story and exploration and develops your fighting skills. Just imagine those 5 quests be done into 100 quests just to get all your skills from 1 - 50 and gear up your character in between every 10 quests. Some quests through the line should open up access to raid instances and ranks with your grand company. All of this could be done with story progression instead of leveling.

It's just an opinion and I'm sure it's too late now.