I'm not 100% sure exactly what the adult expects other than "be good" and "obey me." So, you've just given me an idea. Maybe we need to all sit down together and have a "meeting" so that DS gets it spelled out.
We have already told DS he may be kicked out. But...in actuality, there is a complexity there (they need him to compete) and I don't THINK he would be. Or...it would be stupid of them. I think it's an empty threat.
"Empty threat" sounds so adversarial, like you're dismissing this guy's seemingly legitimate frustrations as a failure to understand gifted kids. Being gifted doesn't excuse a child from being respectful to someone (who may be volunteering his time?).
Honestly, from what you wrote, it sounds like your son is talking back and pushing the instructor's buttons, which is quite disrespectful. Your son may think that what he's doing is funny --- maybe this is a good opportunity to teach him that just because it's funny to
him doesn't mean it isn't legitimately aggravating to the other person. This is a good social skill to learn.
Yes, kids will be kids and all. I get that. And your son is very young, and if the other kids are older, that's hard. Maybe he can start to learn to behave like big kids. I used to tell my kids, "Look around at the other people here. Are they making loud noises/acting hyper/whatever?"
Seven is old enough to know that arguing a detail to avoid responsibility for a larger bad behavior isn't okay, and that the appropriate answer when you're doing something that bothers someone who's there to help you is, "I'm sorry; it won't happen again."