[QuickSilver]

I use a retractable leash for the same reasons - I keep it short when we're crossing the street, and let it out all the way in the park. However, there's one thing I don't like about it. My dog is only 3 lbs and sometimes the force of the leash retracting actually pulls him off the ground! Also, when retracting, it can snap on his ear or the side of his head. Just stuff to keep in mind.

Make sure to use a harness rather than a collar to protect your dog's neck.

You are correct that the dog is supposed to be on your left side. I haven't had much success in keeping my dog on the left, and I have the same issue with giving him treats.

I was able to get him to keep pace with me pretty easily. Whenever he pulls ahead, even one inch, I say "Uh-oh!" in a sing-songy voice, turn 180 degrees and start walking in the other direction for a few steps. When he's re-focused on me, I resume walking in the original direction.

If he's crossing in front of you, I've heard it recommended that you step unpredictably - step really far in the other direction, deliberately step in front of him, etc. This is supposed to teach your dog that he needs to stay focused on you, because who knows what you'll do next.

For meeting people, I would snap his leash a bit and say firmly "let's go" without breaking pace. You will probably need to do this over and over again. However, if you make an effort to be consistent over the course of every walk, I bet he'll get it in a few days.

I also verbally praise my dog frequently when he's beside me. If I'm working on reinforcing it, I treat him every half-block or so. I'll also say his name and drop a treat if he immediately looks up - again, training him to pay attention to me while we're walking.

The thing that drives me nuts is that I can't get my boy to consistently sit at crosswalks. If I have good treats, I can actually hear his little butt thunk down when I tell him to sit. Otherwise, he wanders around in a little circle and maybe sits and maybe doesn't. I have been working on this for MONTHS. I guess that's a signal I need to try something else!

Oh, also, FYI: do not let your dog pull you. If the leash pulls tight, stop dead in your tracks until your dog relents. Otherwise, your dog will walk you, rather than the other way around.