The exp is already such that a fresh character can hit 80 on a single class almost without needing to do a single extra dungeon or roulette, and will definitely do so without any level up walls if they do roulettes every day with MSQ experience. I think the exp situation is just fine, only thing I'd say is maybe beef up the ARR beast tribes just a bit, because your leveling options are pretty scant pre-50 unless you just wanna PotD all day.

And it's a Final Fantasy, the story is important. If you don't care about the story, unironically go play another MMO. I understand that it can be daunting starting out, but the story is kinda the core of the entire experience. And you can skip it if you don't mind paying a bit extra. The game has issues that could use fixing, I'm not saying it's perfect. But aside from ARR's length (which is getting help next month), I don't think the story is one of them right now.