best race depends on ur oponent obviously. its true that Undead rogues are imba against at least 2 classes (lock n priest), cuz of fear/seduce. But vs these classes u should have a tactic that doesnt involve using ur racial traits otherwise u are truly lost. vs lock try Ambush - Vanish - CS no backstab SS or w/e and then KS with 5 points, stunned for 6 secs u have full energy u can pop 2 backstabs and a gouge, if the lock has succubus out just throw a grenade(engineering is prolly the best prof for rogue) and blind her, the lock cant do shit he/she is stunned, ofc if u have shadow reflector just use that
. As for shadow priests, cuz holy priests are like paper, do ur stunlock but give urself a few secs from ur last stun to move away from the Psychich scream radius ( works fine for me im NE) and bam wasted a cooldown and go back in to rape the thing.