I am new to this game, but am enjoying it very much, especially crafting and gold saucer. Something I've noticed though is that this game has a very slow, laggy, or unresponsive combat system, even with ~50 ping. The primary cause of this is poor lag compensation. For many years, shooters have effectively implemented lag compensation to make games feel very responsive, and there are even some MMO's that have some very good lag compensation. If there is one issue I have with FF14, it is the pervasive lack of lag compensation and resulting poor game responsiveness. It is my opinion that by implementing lag compensation or at least work around poor game responsiveness, the enjoyability of the game can be greatly improved.

The following are a few examples of this kind of issue and suggestions on how they can be fixed.

1. When you move, stop moving, and then immediately try to use an ability with a cast time, your ability will be interrupted. And it will take a few hundreths of a second for the ability to be interrupted after casting. The problem here is the game processes your movement input server-side before determining whether or not you are moving while casting, resulting in movement needing to cease a few hundreths of a second (or longer for high ping players) before attempting to cast, and resulting in movement being able to start a few hundreths of a second BEFORE casting ends without interrupting casting.

Ideally, the interruption of abilities should be based upon the timestamp of movement and the timestamp of the ability, at least only during PVE to avoid unfair advantage in PVP. This would make the game feel more responsive because:
A. Attempting to cast while moving will immediately result in interruption.
B. Attempting to cast immediately after ceasing movement will not interrupt casting.
C. Attempting to move a few hundreths of a second before casting ends will interrupt casting.

2. AoE markers disappear a few hundreths or even several hundreths of a second before the AoE's appear to hit targets, and AoE's can hit targets even after they have moved out of the AoE's several hundreths of a second before the markers disappear. Although these two are similar problems, it is possible to relatively much more easily address the first by simply altering the duration of the AoE markers, while addressing the second would require implementing lag compensation, but proper lag compensation would address both issues.

Since people with different pings will see AoE markers disappear at different times, a happy medium can be used to bring the time when AoE markers disappear and AoE's hit closer together. Generally speaking, the issue can be solved by increasing the duration of AoE markers by an average of ~100-200ms.

It's true that prolonging the time between when you have moved out of an AoE and when the AoE marker disappears will make it more obvious that the game doesn't acknowledge what you see client-side, but when the marker disappears closer to when the hit actually happens, you won't be surprised by the timing of taking damage. In other words, you will know you will either be hit or not hit close to when the marker disappears, and you can check your HP bar or floating damage around the time of the AoE marker disappearing, as opposed to several hundreths of a second after the marker disappears.

3. Skill queuing should be increased from 0.5s, especially since I think the 0.5s queue period is reduced according to ping, and may probably be almost undetectable for people with high ping. Any small amount of increase will result in fewer wasted key presses. After playing for a few hours, it gets tiring trying to play at your best all the time by queuing in the small window, since it requires keeping an eye on cooldown timers to find out when to prepare to button mash, and the button mashing gets physically tiring. I imagine just increasing it to 0.6s or 0.7s would make the game noticeably more relaxed and smooth, and personally I don't know how it could harm anyone by making the queuing up to 1s, or even 1.5s for people with high ping, if the queuing is limited to PVE and not PVP. There could be an option to limit queuing period for each player if they feel skill queuing detracts from gameplay.

4. There should be a toggle to hide mouse and go into mouse-look mode, like shooters usually are. I know of two MMO's that do this and default in mouse-look mode, using Alt to toggle between the two. It is possible to make a macro with a third party program to do this, but I'm sure many people would appreciate the feature built into in-game options.

One more thing I wanted to mention, registering for this website requires you to select a main character by clicking a tiny star at the upper left of a character's portrait. Extremely unintuitive design, I had no idea why nothing was happening when I clicked my character's portrait and "Save changes", it just kept sending me back to the same page and wouldn't let me do anything until I used google to find out about the star. Please at the very least write on that page that it is necessary to click the star before clicking save changes.