I've been giving FFXIV a fair shake and I'm in love with cross hotbar system. That said, I'm still bugged by the arcane "tab target select" mechanic. Of course this wouldn't be an issue with a mouse, but then I would be faced with another bugbear I have: the old-fashioned "click and drag the mouse" to turn the camera.
Some recent action style online games have taken to incorporate a crosshair and the camera would move with your mouse like in a shooter. The mouse cursor is toggled on with a button press or when you open a menu. Even though FFXIV is not an action style oriented mmorpg, I believe such an option for a crosshair and camera control might be preferential for some players.
However, my major concern is not for the mouse, but for the gamepad; adding a crosshair and using it as a means to select a target could be incredibly useful for quick, accurate target selections. The tab targeting will still be there to fall back on.
A sort of temporary simulation of what a crosshair system would feel like on a gamepad is to place the virtual mouse cursor on where you would like the crosshair to be and use it to select a target. Unfortunately, the cursor disappears after selecting a target and you'll have to turn the cursor back on afterwards. The crosshair could basically be a cursor that is perpetually on.
You've already done plenty of good work SquareEnix and thank you for already providing players with so many options to fine-tune the game to their preferred experience.