My greatest concern about leveling potions is that newbie players might feel pressured to use them. For leveling potions to be meaningful in this game, they would also need to skip storyline content (otherwise, what's the point of being instantly high-level, if you can't do any of the high-level stuff?). New players might not understand that by using these skip potions, they're essentially deciding to skip the first two books in the series and start right off reading the third.

There are players who could care less about the game's storyline - but there are also those that do. If their FC-mates are telling them that they should use the potion so they can get to the "good stuff" faster, only to discover that endgame is too difficult or just plain not fun for them... If endgame's no fun, and they've thrown away their chance to enjoy the story, there's not a whole lot left for this game to offer them.