Nothing about not being instant is bugged, I realize it's a design choice, however it is flawed. It's a bad design choice, and thus it is flawed.
Take bene for example. This is to be used when a healer is losing control of a situation, needs a second. They're chaincasting spells. The time they take to pop a bene, they expect it to go off.
And like I said, the warrior stun doesn't appear to connect until the axe-roundhouse lands. That's either intentional or part of network delays.
I just think... when you mimic so much of a game because they did it so right that you want to copy it, you should consider why they made each of their choices. This game has extremely fast-paced combat, and as such, the interface should be the pinnacle of smooth reactions.
Can't sleep, clowns will eat me.