The rope halter will really get him off of the lungeline. Thin rope is a lot harder to lean on than a wide nylon strap. When you get him going on a circle and decide to change directions, switch hands on the rope and lunge whip (A stick/string outfit is better, but I used a dressage whip with baler twine tied to the end before I found my reasonably priced stick). Your pony should now be moving forward, and the hand holding the whip or stick should be the hand closest to his nose. "Reel in" the lungeline, an arms length at a time, pointing up with the hand holding the rope in the direction you want the pony to go. The whole time you are pointing, be in front of the pony's girthline (the driveline), and spin the stick towards his nose. If he doesn't respond, take up more rope and try again. If he doesn't respond even when you are close enough to touch him with the stick, tap him on the muzzle with the stick, he MUST listen. This tap should stop him and drive him in the direction you are pointing with the rope hand. The tap is easier to effectively deliver with the stick, as a whip can "sting" and be more painful for the horse, and is also more difficult to control at the tip. This is the "watered down" version of Lunging for Respect, Stage 2. Ideally, master stage 1 first (on circle, stop, disengage hindquarters and look at you with 2 eyes), but stage 2 will get him to turn and be more attentive to you. My new horse came to us knowing NOTHING about lunging AT ALL. Within 15 minutes he was beginning to understand what I wanted with this method. This is an Natural Horsemanship style lunging, so lots of changing direction and speeds. When you get the respect you need, you can do a more traditional style of lunging (for correct gait, frame, etc), but don't worry about that until you have solid control of your pony on the ground and on his back.
I totally get the attitude of the people you were describing. We have a lot of die hard gaming riders (mostly kids, 10-18) whose horses have no manners whatsoever, yet they throw kids on them and set them loose to burn around a barrel pattern. Most of these horses take off bucking, rear until they get the OK to run, and half wreck into the gate on the runback. I know
that most of these horses don't get any work done with them except the showing.
Here's a link to the kind of stick I use, but I have seen better prices. Training Stick and String at horsefriendly.com Tack Shop
Like I said, I've used a dressage whip with baler twine tied to the end before, so...
That "studdy" behavior has a lot to do with his lack of respect and he perception of himself as being higher on the pecking order than you.
I hope that helps!