This may not be your problem, but it is very important none the less. As much fun as it is to let your horse go, we never gave our horses free rein and let them 'pick their own speed' until they would consistantly maintain the gait that we wanted, whether it's a walk, trot, lope, or gallop.Also you are going to have to be consistent no racing off with friends while you are trying to stop your horse jigging otherwise you will be sending mixed messages and your horse won't know what you expect.
That is a very good point. Your horse sounds super hyped as well as unruly and undisciplined. You said that you are doing barrel racing and cow events, when you school him for these events do you ever do slow flexing and bending excercises or is it all gallop, gallop, gallop! Even in an arena you can school a horse quietly which will then help out on the trail.Perhaps unrelated, but what are you feeding him?
How much feed/soy/corn ? If he's running fences like a stud, he must be really hyped, and I would seriously look at what you're feeding.well i do feed alfalfa most of the year and we feed Sr. feed(we just give it to all of our horses),soy beans, corn, and his minerals(i dont know what their called) Is his grain making him the way he is because if it is i will just either cut it off or give him less