If there is one thing I consider valuable that you could implement from another MMO, it's World of Warcrafts practice dummy.
For those who didn't play WoW:
Practice dummies were in each city and had varying ranges (level 60, 70, 80, heroic boss level). They were stationary targets that didn't attack or move and just allowed any person to target them and blast away spells, melee attacks, items, whatever you wanted to do. They never die and mainly serve the point to practice your class rotations, parse and measure dps with different gear sets, testing out macros or items, and whatever else you can think of.
I think this would be an invaluable tool for the players of FFXIV. It would help players practice there combo's and test how different stats affect them, and in the future when 3rd party add-ons can be used in the game there could be a lot of additional use that helps people to play at a higher skill level.
I'd suggest putting them in every city, maybe in an area that doesn't have as much traffic to help spread people through the city more. And I'd also suggest making several different levels (e.g. 25, 50, 60, 65 [primals]).
It would be great if this could be seen before 2.0, however unlikely that is. Maybe it's possible to implement a temporary solution (e.g. a Goobbue that doesn't move or attack and never dies). It doesn't have to be fancy.
Anyway - this is something I think would help a lot of players learn to play all classes and help with learning combos.
EDIT: JP makes a post a week after me, rep post the same day. I make this post... no comments for 2 weeks, then a rep post and BOOM! this blew up fast. Only took a rep post! and a 2 weeks.