The problem is not bonuses, failing does not reward item gil marks or other rewards, the issue lies in the balance of the sp obtained from leves
the sp can range from 1,000-20,000sp between r40 leves, that's a huge variance
Another issue is with the randomness of the leves, and the time to perform many different leves vs repeating the same sets that can be failed
failing insures that all members in a static group have the same leve next time, thus allowing for full links
while completing means that each member will be issued a new random set of 3 out of the 9 for each camp
gil, currently has very little value, and is very easy to obtain, marks do nothing for anyone once all guild items are purchased for a class, and can't be used or traded in for a different class.
the items rewarded are often gear that has been so vastly obtained, and so pitiful that you can barely give it away
players that are using this method on leves are looking to level quickly
leves currently allow 30 mins to complete
but vary from 1-30 mins to complete
and reward varies from mob to mob regardless of rank
balance should be in time and sp, you don't want the completion time too short, as it would create an imbalance if the sp is the same
as for removing this problem, bonus for completion time, fixed sp amount based on stars, aspect player level number of party members, to be rewarded at the end
or, simply make leves solo content, make parties go do grind parties
honestly, i'm so sick of leves if i never performed another one, it would still be too soon