These are just some ideas I've had while talking with friends who play. Don't mind criticism, just keep it constructive and civil. 
-A glamour plate per class, perhaps with a couple extra for swim/civilian/nightwear (could even charge for them in the cash shop, I know a few people who'd pay)
-Blue mage queue system that works like normal (autofill) queues instead of party finder
-A means to gather mats while offline at a greatly reduced rate (gain class XP too), could also apply to crafters
-More control over what your retainers look for for you, not necessarily a guarantee but an increase chance of getting -item type here- possibly also including from -this level bracket-
-Level skips for crafters/gatherers, including mastery (another one I'd personally pay for...)
Continue reading...
-A glamour plate per class, perhaps with a couple extra for swim/civilian/nightwear (could even charge for them in the cash shop, I know a few people who'd pay)
-Blue mage queue system that works like normal (autofill) queues instead of party finder
-A means to gather mats while offline at a greatly reduced rate (gain class XP too), could also apply to crafters
-More control over what your retainers look for for you, not necessarily a guarantee but an increase chance of getting -item type here- possibly also including from -this level bracket-
-Level skips for crafters/gatherers, including mastery (another one I'd personally pay for...)
Continue reading...