So thinking about my disappointment in Eureka for so long made me want to turn to something constructive. Instead of brooding over how much I didn't like Eureka, I decided to put my energy into proposing something I as a player would find very interesting as content in this game.
Namely, make use of the arena that one sees in the Ultros fight, Halitali, and Samurai/Paladin quests.
The way I'm thinking of it, it could be a string of randomized fights that have both a novice/advanced version and a single/party version. For single matches the pools could be specified for each job, so that the novice version would be a great way for classes to practice and learn the job's skills at 70 while the advanced version would be much more challenging and interactive per-job (perhaps a Black Mage would be forced to use sleep and time Mana Wall, a Dark Knight would have to Living Dead and click on something to heal and clear Walking Dead, etc.)
Party could be like some string (7?) of fights that are randomized but fairly intense, like floor 190-199 of Palace of the Dead or perhaps a savage Aquapolis. Since it's randomized and certain party combinations would be more suited to some parts of fights than others, it'd be my hope that parties would detail unique strategies at the start of each round based on their compositions.
Of course, give it some incentive to do every day...some 10~15 minutes per day of challenging oneself to some tomestones and of course the usual little mounts/glamour trinkets over time, etc. This serves a lot of purpose, as sort of in-between casual and hardcore content, a thing to spend time on each day, a way for new and returning players to ease back into the mechanics of their job and then challenge themselves...
What do you think? We could even see Siegfried/Ziegfried and Shadow as possible enemies in singles, or have the 4 grand company leaders as a Halitali (Hard) style fight in the random pool of party stuff, there's lots of possibilities.