Well we should start with something small and realistic. I'm talking about Hall of Novice and the training dummies.

Hall of novice needs an upgrade. Not just for jump potters but generally the whole populace. It should be a place where respective job trainers can teach some advanced combos or tips.

Training dummies need more than "beat this thing under 3mins". They should have the ability to be tweaked to auto-attacking you, have them set in groups (to test aoes) and other settings to allow different testing.

Those are things I feel SE could realistically do if they were serious about it and as I've mentioned, its a step.