I can honestly say, I doubt I'd make use of Boxing or Kick if made into a useful attack. I'm trying to remember if Air Superiority was ever worth taking. I could swear there was a time.
I know my Warshade has Arcane Bolt, taken, slotted and used because it's not only, if I recall correctly, better than some of it's other attacks, but really fit my concept well (obviously, the concept not being a WS :p) However, I'm not sure if there is to many combos where it would be better than tier 1/2?
And for a lot of sets, it may not be worth it in the case of Boxing/Kick. Still a melee attack that may not go well with a lot of range characters. Boxing likely wouldn't be best if used with a weapon set at just tier 1/2 levels.
Of course, I think best tier 1/2 levels in terms of damage, so for some it may turn out better for some sets than others.