"No academic consequences for behavioral issues" sounds like a perfectly appropriate accommodation to put in a 504 to me, although you might have better luck treating it like spelling for a dysgraphic kid - "No reducing grades for behavior unless the assignment/assessment is specifically intended to teach/assess behavior."
YES!
And it may not change teacher behavior, but I don't see anything wrong with saying "DS does not respond well to raised voices" and "DS does not understand sarcasm," either.
We have in the past used a Behavior Intervention Plan to specify how teachers should respond to what they viewed as problem behaviors. That form literally allows you to describe problem situations and specify the correct response to those situations-- what may or may not be done.
It doesn't solve all the problems, but it is useful for everyone to agree on the boundaries and strategies far in advance of the inevitable incidents.
