Usually when IG events are super difficult, they can be ended the next year (even if non repeatable), like the clovers event. And if not playable next year, usually events are finishable by the most. But here, from what I read it seems to be as difficultly finishable as clovers event BUT not finishable next year :
"This event will not be repeatable, which means that 16th Birthday items will not be available to win next year."
More than that, beta players tried this event and concluded it was tough to gather 680 tokens in 3 weeks (cause the duration in beta is 3 weeks) but in regular worlds it's only 2 weeks long, which means same amount of tokens needed for the set but less time and less quests we can complete. I'm a bit worried this event may not be endable without buying tokens at the shop. In any case lots of players won't be able to participate to it (it requires craft level > 300 and from what I understood quests aren't made for low level players) and that's sad for a BIRTHDAY event, to make things so difficult/restrictive while the main point should be to allow as many players as possible to win the celebration prize ...
Also, it'd be good to have access to the list of the daily quests before the event starts, cause if we have only this year to try to win the set, it's important we know in advance the days where there are FF daily quests particularily (knowing we need to dig one day before to have a battle the day where the quest is on). In worlds where there's a battle every day that's not a problem, but it could be a big one in inactive worlds. Same with quests requiring to gather mats, it could be pretty usefull ...
Or if too early to give the details of the quests, maybe someone could at least tell if the first day there's a FF daily quest, and if yes, if a win is needed ?