You’re certainly correct that your horse’s behavior poses a serious danger--to you as well as to anyone else who turns him out. He could easily run over you or kick out at you in his rush to the pasture. Another downside you might not recognize is that his last thought about you before he gains his freedom is “Let me go, and get lost!” Over time, this lack of respect for your authority will trickle into other aspects of your relationship.
I also agree with your vision for how you’d like your horse to behave at the turnout gate, and I believe it is a goal you can reach. The training steps I’ve outlined below are a general guideline. You may need to spend more time on one stage of training than on the others, and if your horse begins acting up again, you may need to backtrack to remind him of what he’s already learned.
The retraining process will take time, and I’d suggest that you schedule the first session on a day when you can devote a significant chunk of time to it and preferably after a long ride. This way he is more in a frame of mind to take in a lesson. Then continue to make time to deal with this issue for at least a few minutes each day. The fact that your horse’s behavior is the same whether or not his herdmates are present indicates that this is a wellestablished habit, and you will not be able to change it in one session. It is important that you do teach him turnout manners regularly because the respect you earn from him will affect all of your activities with him. During your training sessions, remember that your primary goal is not specifically to turn your horse out, but to change his behavior as you do so. Of course, in the end, you will get him into his field,