The only raid which is a real challenge is Bixie, rest are pretty straight forward.
WK raid... pretty straight forward, keep the NPC healed and control waves of adds (3 waves) then the boss... boss has a KB spell, nothing to really worry about I think. Kill the ranger mobs first to reduce AE stacking on players.
Range dps xulous to make it a bit easier and use melee for the maggots.
Bixies... make sure you know what the drum clicks do and use them appropriately.
ie. first mini Targets AE should be cured by healer drum click which can immediately be overwritten with melee click (well in like a tick or something)
Second mini need to use hybrid click to dispel and make sure melee aren't stupid and die repeatedly on the DS.
Last bit use the dispel again for the heal buff on the minis.
What ever you do, don't burn the boss... you'll get over run with bixies really easy.
Also don't try and kite anything.
Neriak... burn one, then then kill the other rather quick as well while keeping the ghouls dead (they power up) ... follow emotes.
Only seen/done these since live, nothing on beta.