I notice all sorts of odd lag in this game: sometimes when using skills or abilities, sometimes with animations, others even when just... entering text. As easy as it is to say:
Doesn't matter how much bandwidth you have, you're still sending the message to Japan and the round trip time is going to be ~250-300ms at best.
I think that it's telling that I never noticed such lag when playing FFXI (which, I assume, also comes from Japan), and also that, even in the video posted today, the Goblin's HP drops several seconds before an animation occurs (I assume the dev. team is playing in Japan).
In short, FFXIV has a lot of small issues that it needs to work out, issues that separate an alpha/beta game from a release game, such as bad UI performance and lag for many different actions. Personally, I wouldn't scour the internet for tips on how to fix it until the game becomes more polished.