I prefer having the choice to cast it when I want rather then casting it once and not being able to
Knight Buff Tree: Finally the last tree of knight skill, aerial blow is largely useless and gets in the way of the vastly Aion Gold superior 3 hit combo from time to time.
Impervion should be left at level 1 since at that level it works best, in past experience I prefer having the choice to cast it when I want rather then casting it once and not being able to for a long time, forgoing the defense tree you should be able to max revenge.
And given the skill sets you raised you should be able to do decently in pvp situations though revenge is rather useless at knight stage with your miniscule mp pool, but there are times where it works well like turning it on and jumping into a jester's death lock and watch him kill himself.
Next off pressure, yet another launch, now people will go "but pressure does so much more damage then other launches" - okay you have a point there but then consider the MP cost for pressure a skill that does maybe 1.2x-1.4x the damage of shoulder tackle.
Basically it cost 2x-3x more mp to do less then 1.5x the damage? Quite a waste but still put 1 point in as it hits knockdown and inflicts knockdown. And it’s still a good pvp skill.