Yikes! I am not an expert on IDEA, but don't let them drop his services if you think he needs them. I believe they cannot change his IEP without your consent. If you don't sign the new one, the old one remains in place. He won't have new goals, but at least he can keep the accomodations.

I think you need some outside testing. A diagnosis of dysgraphia from an outside psychologist is going to be hard for them to ignore. I also agree with getting an outside OT assessment. You might also want to talk to an advocate. Try the yellowpages on wrightslaw.com to find one.