But that's not how its going to work. Those reductions would leave vast gulfs of abuseable terrain that can and absolutely would be abused endlessly. Or, if it does, players will get some sort of immunity to CC for a time after, or swiftly accruing stacks of resistance to it, etc, so on, so forth.
Point being, if you've ever PvP'd in a wow-clone environment, what's going to happen with regularity and commonality will go like this: Most of the time, your CC's won't be worth anything at all and you're going to need some other way to buy time to do anything worth mentioning at all. I predict that summoners and white mages are going to be excellent casters, but no, black mage is pretty much dead in the water unless we get some increasingly bizarre departures from how anything works in PvE for BLM's.
These classes...were not designed with PvP in mind. It doesn't take a game designer to tell that, or at least it shouldn't. BLM...no. No, this isn't going to go well at all without drastic alterations.
Not ...at...all.