Choke chain
Well, if your dog is acting this way, You should definatly not have him on a choke chain or anything he can slip out of - try a harness, you have much more control because you have a hold of him by the body not the neck and if you pull the leash up the front legs are off the ground = less power that he has to pull away from you - I am not saying to lift him off the ground, I was just explaining how a harness works.
How do you act when a person or a dog comes around you guys? if you are telling him " its ok, good boy etc." to calm him down, all you are telling him is that he is good for acting this way even before he does it.
It sounds like he is nervouse and scared of the people he see's if he is hiding between your legs when people try to pet him.
try and make him sit when there are other other people/dogs around and give him treats when he acts calm and the first sign that he is starting to get excited stop and try to get his attention - teach him good things come from ignoring other things or just paying attention to you gets him good things.
Do you keep going for the walk when he does this?
You might try to walk until he starts to act like this and then stop the walk when he acts badly, but I think this would only work if he really likes his walks and if you start doing this right next to your house then build up the distance away from your home, maybe even ask someone to walk by, or even a friend to try and help you with this.
But the best thing to do I think would be to read a book or consult a professional if the info you get from people doesn't work or if it starts to backfire on you.
