Titan issues that need addressing.

[Cutie_McSnuggles]

First, I find it difficult to believe that most players monitor Titan's cast bar. Heck, going by the number of interrupt opportunities that pass by unchallenged on everything from the average mobs to dungeon bosses, I would argue that most players aren't watching cast bars anywhere. While it's fantastic that the fraction of people on this forum who are participating in this thread (which make up an even tinier fraction of the people playing the game) are apparently all cast-bar watching pros, as someone who is always tanking I feel like I can safely say that most of the time the only one staring at cast bars seems to be me (as I'm rarely able to count on the average player to help interrupt anything).

While I can sympathize with the idea of wanting cast bars and animations synced. If you're not paying attention to cast bars then how did you get past bosses like Coincounter and Chimera who's major attacks have no AOE indicators, and how do you expect to deal with mechanics in Coil many of which also have no AOE indicators? Paying attention to cast bars is a required skill to succeed in this game.

Also, it's the tanks job to stun bosses. Good DPS will hold off on using stuns during most boss fights so they won't build up immunity.

[Gyson]

If you're not paying attention to cast bars then how did you get past bosses like Coincounter and Chimera who's major attacks have no AOE indicators, and how do you expect to deal with mechanics in Coil many of which also have no AOE indicators. Paying attention to cast bars is a required skill to succeed in this game.

While, as the tank, I may be taking care of Dragon's Voice and Ram's Voice on Chimera, you can be certain there are many players on those runs who aren't even aware of these mechanics, and yet get through the trial successfully because someone else (e.g. the tank) was taking care of it. Point being, that the average player may not be paying attention to cast bars is really of no surprise to me.

Also, it's the tanks job to stun bosses. Good DPS will hold off on using stuns during most boss fights so they won't build up immunity.

I disagree, and I don't think it's the tank's job exclusively. While you certainly don't want DPS firing stuns off at random and making it impossible to (example) interrupt Ifrit's eruptions, a well timed interrupt from DPS is both helpful and welcome. Using your Chimera example again (an encounter which I farmed over a 100 times), many a time my silence has been on cooldown when Ram's Voice popped up, only for a helpful Bard to save the day with a well timed and intentional Blunt Shot. I think in a perfect world the entire party should be using all of their abilities to the fullest (and intelligently) to guarantee success.

But, we're getting off track.

[Viridiana]

While I can sympathize with the idea of wanting cast bars and animations synced. If you're not paying attention to cast bars then how did you get past bosses like Coincounter and Chimera who's major attacks have no AOE indicators, and how do you expect to deal with mechanics in Coil many of which also have no AOE indicators. Paying attention to cast bars is a required skill to succeed in this game.

You picked a few bad examples. Coincounter is like the old bosses in 1.0, where you can derive everything you need to know to kill him from his body. Is he twirling his club in a circle? Swipe is coming, tank run through. Did he turn to face a non-tank? Everyone stack behind. Is he focusing super hard on his club but not moving it? Tank stun or everyone run out.

Cutter's Cry Chimera the EN client tells you everything you need to know without ever looking at his cast bar. Blue eyes? Run out. Violet eyes? Run in or way out. Orb chasing you and violet eyes? Run way out. Everything else has an AOE indicator.

Many of the mechanics in coil have an indicator other than the cast bar or can be completely avoided with positioning. The only one I can think of off the top of my head where the cast bar is your only indicator is Twisters. Maybe could argue Lunar Dynamo, but Dynamo probably won't kill you if you get tagged by it and can be avoided just by staying at melee or max range. Actually, I guess the old High Voltage in BCoB, but that only required two people in the raid to watch it. So let's see:

T1: High Voltage on ADS. All of Cad's attacks have AOE indicators or are meant to be healed (spit attack)
T2: High Voltage on ADS. Allagan Rot is what killed people, but the cast bar does nothing for that.
T3: lol
T4: Pox, I guess?
T5: Death Sentence, Twisters. Everything else had an indicator of some sort.
T6: Everything has an indicator
T7: Watchig your debuffs more important than the cast bars.
T8: Can't really speak to T8, but don't remember anything that requires watching cast bar.
T9: Dynamo and Heavensfall if you're in weird positions. And you can even save yourself from Heavensfall for many classes.

I can't really speak for FCoB, but nothing I remember seeing about them necessitates watching a cast bar. Granted, I could be remembering wrong. . .