[alaskayorkie]

I can't really help with the anti-social part, but I'd strongly advise against using a choker or any kind of collar. Yorkies can and do get tracheal damage easily, and pulling hard on a leash can do it.

Instead, go for a good harness. Yorkies are small enough that you can control them just fine in a harness.

To get him to stop pulling, I've heard you can just stop when he pulls. Switch directions. Don't let him dictate which way the walk is going. When he does right, reward him with a treat.

Another thing you can do is teach him to heel. Hold a treat at your side between his line of vision and yours and tell him "heel" or "watch." Walk a few steps, and reward him the second he does it right, then gradually increase the time between rewards.

I don't think any of my advice will solve the problem you describe, but it may help.