At this point, I could actually see myself being happy even if animation locks were left unchanged, and even if the rate in which abilities are used remains the same, as the devs are insisting will be the case... AS LONG AS:
(a) The word "instant" is changed so it is no longer misleading players. While the delay following these abilities may be less than 2.5 seconds, showing the word "instant" instead of a delay time implies a delay of 0 seconds. In reality, this is not the case, so they are not truly instant. These "instant" abilities also imply that they do not obey the 2.5 second GCD of other abilities that are used beforehand, which would lead one to believe that they can be used immediately after an another ability, but in reality they are still subject to the animation locks of abilities that are used beforehand. That is not instant either. If you are going to keep the timing how it is -- which is not instant -- then please, don't hide this timing behind the word "instant." This choice of language is only confusing players. Any other choice of words would be better than how it reads currently.
(b) We get some sort of visual indicator for animation locks on our off-GCD abilities, similar to how the GCD is currently visualized on our other action buttons. Continue doing things as intended and keep the timers how they are, that's fine. Just let me SEE how they are. I don't like being forced into spamming buttons simply because these timers are being needlessly hidden from players. If these timers could just be given a form of visualization, then the lifespan of my input devices will increase dramatically, I will be less likely to develop carpal tunnel, and my significant other will be able to sleep in the same room without me having to listen to them complain about how I should come to bed because my keyboard is making too much noise~
(c) Abilities are changed so they are considered to go into effect immediately when an animation lock begins, instead of after the animation lock ends. Again, keep the animation locks at their current duration and maintain the current pacing of ability use, I don't care. Just don't put my abilities on their ridiculously long cooldowns without them ever taking effect. (*cough* Hallowed Ground *cough*)
If the timing between abilities is not going to change, then at least change these three things, please. They have no effect on the pacing of abilities/combat, because they have no effect on the duration of ability locks or animation locks themselves, allowing the game's tuning to be kept the same and negating the concerns about difficulty that were raised by the devs. Yes, you can keep your animation locks, your visual fluidity, and your cherished pacing of combat and abilities, and I'll get over it in time. Just please, address the needless unpredictability of it all. Is that really too much to ask for?