Your horse is anticipating your lope offs. I would practice setting him up for lope offs but not ask for them until he gets over it. The spins, you didn't reaaly help him by setting him up after he fell through the stop in the middle. Schooling show, home, pull him into the ground when he ignores your stop cues. He is being lazy, make him work if he doesn't try hard. If I have one that gets lazy like that I will make him work on some small circles then run down the arena and ask for a stop again. If he doesn't try hard, make him work. If he puts some effort in his stops, then he gets a break. Same with the turnarounds. He wasn't set up and he wasn't putting any try in them. He was just lazily swapping ends. Make him trot some small circles, then let him come into a walk and let him step into the turn around. If he gets sucked back and starts swapping ends push him out and ask him to trot small cricles. He will figure out that doing it right is easier than being lazy and doing it wrong. Rushing through leadchanges could be from being spurred into the change, anticipation or not enough speed and not being setup for it. Lots of counter cantering and counter arcing on the circle without a change, get him relaxed and get him balanced. Get him outside of the arena and do something else on him if you can for a little while, you guys look cute together, I would hate for him to get burned out :)
I DON'T LEAD 'EM AND FEED 'EM, I RIDE 'EM AND SLIDE 'EM.