BLM needs some love and RDM needs a nerf

[Krisom]

Furthermore, the "nullifies draw in and knockback" completely doesn't work, or I haven't encountered a moment where it does.

The problem with this is two-fold and it comes with bad design.

The first problem is that many mechanics for some reason do not let you take advantage of these abilities, for example on DRG I had an idea that if I were to be targeted by Susano's knock-back and have a bomb on me I'd use Arm's Length so I don't have to sprint back to the group. - However I should have known that it knocks me back regardless.
Arm's Length and Surecast are in no way game breaking in that fight because most of the time you will be targeted by a stormcloud, the very rare moments (once where it matters in the fight) you're not targeted it'd be perfect and would reward players who utilize these abilities wisely.

The second problem with Surecast is that when you begin to cast a spell, the effect wears off. I am unsure if this affects the knock-back or not but it's very likely it does in a way that it wouldn't work any longer.
Would it be game breaking for Surecast to be a buff that lasts 10 seconds for every cast during then? Probably not, but I don't see any reason why it's in the state it is. Increase its CD, reduce the duration of the buff but atleast make it more useful than it is now.