Quest based leveling: Future problem?

[Rokien]

But what if for example for the person who didn't know better and did ALL their 1-20 quest cause it was such an interesting storyline.
It would be weird, but I think that if you switch class so should the progress of current quest lines. This prevents people who decide "Ha, I'll start the quest on my level 10 MRD, and finish it on my 50 THM, and then collect it on my 10 MRD!"
But hey, if perchance there are like over 1,000+ new quest being added, shouldn't be too much of a problem.

Dungeons, and quests. That is how the future of leveling up in FFXIV is.

--->GO HERE >>> RUN THERE >>>> KILL THING <<<<< GO BACK <<<< GET 10000exp. Repeat.

You can't have that many quests and make them all unique and interesting. Especially when it's going to be like; GET YOUR NEXT QUEST HERE -> (!) FOLLOW THE ARROWS -> Might as well have path follow on this game.