Bard -> ONLY PVE, you just have 2 skills you need to solo: Noise and Moving March/Swing March.. maybe you can bard in pts, but most of them just take int bards, they are even better... still you can try
Cleric -> Good for Pve and PvP, Bless Spell, Holy Spell, Holy Recovery Division, Offering for Fun, you can cleric in pts if you have a bard, you can ress, buff etc... you just have no speed like that bard, but those speed potions are cheap tho
Warlock -> more for pvp, stun for example, sleep, panic, debuffs, dots... for example you debuff and stun someone in pvp and change to warr weps to kill him.
Rogue -> only for pvp, or at pve you solo as Xbow because its more fast due to your range... but you will need a big amount of SP which you btw need for all of this builds! (most less for warr/bard if you just want to solo and dont want to pt as bard), you need 2hand for pvp, axes for stun, shield trash at 1hand for kb, xbow to knock down and daggers to finish. There are some warr/rogues who are very strong in pvp. hard to kill them for some ints ...
A good warrior has to be farmed, always think about that!
Btw as Warrior you should play with 2hand.. its stronger than dualaxes, it does have knock back and knock down. Ya dualaxes have stun for example, but 2hands are stronger! You even crit more often ...