If they do implement auto-attack, I'm hoping that Haste from FFXI will make a return.
You might say XI had slow auto-attack, especially for 2H fighters, but it gets so much faster with Haste equipment and spell buffs.

I'd really like the same system of Weapon Delay for XIV, it would make more weapons unique too, as they would vary with delay and TP gain per hit. It opens up new tactics for equipping yourself.