Bringing the husband along is a good plan. I think some teachers just respond better if there's a united front, and some just respond better to men.
Did the GC say why she thought 1st was an important year? In our area, it's important for learning to read and learning basic math, which your DS already mastered, so hopefully she has a better reason. I can see how behavior issues might cause difficulties, though. I guess I lucked out having a teacher pleaser.
I'd try to get a meeting before school starts if you can.
