In This Replay White-Ra uses an early Harass build against a Zerg Player.

The Build seems to be a 2 gate transitioned into a 4 gate and then later on a robo.

Well my question is would doing this opener be effective or just generally Orthodox against

Terran and Protoss player also?
If so what would be the Strengths and Weaknesses of this build
If not what would be some alternatives to this build against the other 2 races?

Also if this were to be used against the other races would there be some things that might need some changes to be more effective against them?

Lastly what are your overall thoughts of this build and opinions on it