Wait, but...is she a problem for you at home, or no? You say this:
When left to her own devices, she is contrary, difficult, disrespectful to adults (with the exception of family), frequently seemingly "out of control" of her body, her voice, and mood (especially when overstimulated... like at swim class).
That sounds very difficult.
but you also say she is "generally terrific" outside of school. So are the issues limited to school, or no? That would greatly influence my reply.
FWIW, though, my daughter was very very difficult in preschool, and was, in fact, somewhat infamous there. I thought we would have major behavioral problems in school. We have not. Although she has had a few minor clashes and had maybe 3 major meltdowns in K, in general, she's been able to rein it in and has been very well-behaved.
