The main problem about dodging those is the short duration of the enemy preparing the attack. Just increase it by 1-2 seconds and everything becomes dodge-able. Thing is, it will be still easier with people with low latency to dodge, potentially becoming a cakewalk for them.

Now, about Ifrit's plumes, that's a different problem. The server doesn't calculate your position but interpolates it. So if your interpolated position happens to be near a plume area, you're dead. They can't fix that unless they change the way server calculates your position, which most likely won't be possible until the engine switch. All we can do is hope they'll fix it in the new client.