Unique gear like the Primal weapons I agree is a good start.

Each element being aligned to its own attribute and bonus makes for a whole range of situationally different weapons and armour. Vitality boosting swords with damage reduction from Titan, Leviathan dropping Mind boosting wands with cure potency. Wishful thinking, perhaps but totally doable. Would keep people replaying the content.

PLD would have a choice; sword with 5% cure potency, HP drain, damage reduction, evasion, each would be collectable in its own right IF the game presented challenges that warrented that level of tactics. Who remembers tanking In elemental gear? These items are easily plausible, and can be implimented with the current system. BUT they are useless without the need to equip them. This is where difficulty and stategy comes into play.