Are they agreeing to include the results of your independent evaluations in the discussion? It sounds like your testing is less than a year old, which makes it not only unnecessary, but inadvisable to re-test with the same instruments.
As to your list of concerns, most of them do fall in the areas usually assessed by OT, social-emotional-behavioral, and language. The only one I might consider follow-up private testing for is #1, auditory processing, as a good central auditory processing eval usually requires hospital audiology facilities (because of the expensive specialized equipment). If that comes up as a deficit, that would also give you an additional diagnosis, so that OT becomes not a stand-alone service, but a related service. Also, you already have a diagnosis of ASD in hand, presumably from a legitimate evaluator, so the question of identifying an area of disability should be settled (as for a 504 plan). It's more a question of identifying educational impact (for an IEP).
