The race just determines a number of passive traits for the most part. Betazoids for example are less easy debugged and have excellent stealth detection if I remember correctly.
There are some exceptions, though. Vulcans, for example, can use the nerve pinch instead, which is a close range stun and situational at best.
You are best served to go with passive always on traits that complement your build (damage, tank, healer and so on...)