For Swordman:
Dont get Thrust (Its bad dmg)
Try to get Bash 3 for Knockdown Attribute
Choose either Str build -> Gung-Ho, Dex build -> Concentrate
Make some points in Restrain if u wann have that skill (Its nice CC)
For Barb:
Fine as it is
For Corsair:
Hexen Dropper, Pistol Shot and Dust Devil should be max lvl.
Choose if u wann have higher Hook (Pvp pref) or Jolly Roger (PvE pref) and get at least 2 points in Jolly Roger for attribute.
I cant advise for DWA get 1 point if u wanna have it. (Its super annoying to use)
For Shinobi:
Bunshin 5 Kunai 5 is a must!
Decide between Mijin and Katon get 3 points in either of it and 1 in the other one. (Get one for dmg and the other for stealth attribute)
1 in Mokuton (nice defens skill if timed correctly)
Stats:
Depends if uh ave enough accuracy. But 180-200 Dex is more or less soft cap of Atk Speed.
I went 120 point invested in Dex, rest Str -> Reason is i reach 180 Dex with gear (Which is fine for me)