Choose your race based on things like look or lore imo. Yes there are nice racials that you can get but they are in no way a make or break mechanic most times. Even in top end gear for fire mages the difference between a troll and human in perfect gear with the 30% ends out being like 100-200 dps or something non significant like that (if you perfectly time cds and don't move at all while berserk ,or w.e. the spell is, is up). yes if you ABSOLUTELY want to min max then go ahead, but the only reason the dps difference is that high is because you're in BiS with a 30% buff meaning the differences are that huge. Racials shouldn't be a huge huge reason to choose a class unless you're in a top 100 guild. Pvp can be done without the racials it's just a little harder, a racial won't make you get 2200 if you're bad though.