Woo touchy subject!! TL;DR @ the bottom

Some history of my FFXIV and MMO background: Skip past this for my ani lock vs gcd discussion.

I played FFXI for almost 3 years before I quit (quit a few months into WotG...I miss campaign T.T) it and took a break, then I got into WoW, so I've went from animation lock to GCD system.

I was in the 1.0 Beta and have been on and off 1.0 ever since. Recently started playing again very consistently after the jobs were introduced.

Animation lock vs GCD:

Since I've played FFXI before, the animation lock wasn't new to me, so when I came back to XIV from WoW it was easy to readjust. Although the ani-lock overall didn't bother me, I did notice it did hamper my gameplay some, but eh...you just deal with it.

Until I did Ifrit...(As a caster, there is no melee example as I did not use a melee job in my attempts)

Some of it may be lag issues, but since when has FF MMO's been known to have good lag for US players :P

My main job was WHM, so I didn't have to do much...stand near the rock = /win, but when it came time to move from the eruptions or avoiding his dashes I had an issue. (Dealing with eruptions as a caster will be my main example here since whm positioning usually did not need to worry about the dashes in my experience)

Now as far as the whm casting animations (I am a hyur male) my character brings his hand to his forehead and begins "casting" his spell. The cast bar finishes then he extends his hand to actually "cast" the spell, then moves his hand back to it's neutral position at his side. There are two separate animations here that I notice. The hand to the forehead (channeling of the magic), then extending the arm + return to neutral position (the actual casting of the spell). The former is necessary as it's during that time the cast bar is being filled meaning the character is concentrating on casting the magic/ability. I think we can all agree that it is necessary (oh the price of being a caster :P).

The latter is imo the animation most people have issues with as far as being rooted when you need to move urgently.

From my experience if you are midcast (cast bar is being filled, first animation) there is no movement restriction, therefore you may interrupt the cast and move immediately. However, if the cast bar is completed and the cast is going to happen the other animation starts, which prevents you from moving until the hand is brought back to the neutral position. This is where imo most people feel "rooted". So if you factor in an eruption for example, if it comes in while you are in midcast and the bar fills up (whether it be lag, slow reaction time, or just bad timing) you get stuck in that 2nd animation where your character "casts" the spell/ability then you are rooted for almost a good 2 seconds, while the eruption blows up under your feet. This is when that animation is either unnecessary OR it should have been a fluid motion along with movement.

Since a lot of people tend to cling to "realism and immersion" in this game, then realistically if you were in that situation would you not move as you swing your arm out the actually cast the magic/ability at your target? I would say it would be possible. Once the cast bar has been filled, the conditions to allow the spell to be cast have been met, so anything you do after that should not impede the casting of the magic/ability. In reality, I would think after the caster has meditated, concentrated, or channeled long enough, you would not have to stand still to actually throw the magic from you to the target. The magic is more than likely at it's focal point allowing you to simply direct it to where it needs to go since the magic has already been conjured and is ready to be released.

So with that in mind, my character should be able to run and "cast" the spell at the same time once he has finished conjuring it (meaning he should be able to run at the same time he is extending his arm to cast the spell). This is where most of the problems would have been alleviated imo. The same principle applies to BLM, and any other jobs that use abilities that require a "cast time". I do not know what kind of work is required to change something like that, but that's what I think would have been a nice fix.

I remember back in FFXI the same issue happened. Your group decides to run for the zone if you get in trouble. You are casting a spell, and the cast bar fills so you know the cast is happening. If they were in range your character would stop to SLOWLY raise their hand in the air to cast the spell and stand there a good 2-3 seconds to let that animation happen before you could run again (then you remember you forgot a reraise scroll T_T). Same thing in FFXIV. Usually it doesn't bother much until you have to make those decisions to move ASAP or you need to turn tail and run, but the game requires that certain animations must happen before your character can begin the running animation.

Remember back in early FFXIV when your character had to stop to put their weapon away before they could run again when passive and active mode were toggled stances....? They fixed that albeit it's not necessarily the most fluid animation...looks staggered but that's probably all they had to work with, but look how much better it made the gameplay!!!...(at least it did for me).

Anyway that's my take on it. Right or wrong that's what I would have done if I had the ability to change it granted the game design allowed it.

TL;DR

The second half of casting animations should be more fluid. Meaning once the cast bar is full, the character should be able to move without having to transition between casting and walking animations as they cast the magic, but after the cast bar fills up. This would help prevent the "rooting" casters and some melee felt when they had to cast something, but evade a mechanic or simply just {Run away!} quickly.