Having just gone thru the process of getting max fame in all abyssea zones I can tell you that some quests do seem to give more fame than others but that's probably because they were easily repeatable. The zone I had the easiest time was Uleg and the hardest was Atto, but in the end if you do enough of the repeatable ones you will max out (at the cost of many many stones). Don't give up, it can be done.