Oh boy! First of all, they cannot tell you that your son cannot have OT because their therapist resigned. If there is a documented need, they must provide it, even if they pay a private therapist to do it.
So, let me back you up a step... when was your son EVALUATED by the school district. What is the date on the eval report, and what are stated as his needs in this report? Did the school meet with you to review the results of testing?
The IEP does not have to have objectives or benchmarks as of IDEA 2004. It does have to have measurable and attainable goals.
Karolysgirl is right about the OT, not having one can't be the reason why he isn't getting it. Does it say in his IEP that he will get OT or PT? IF not, then they don't have to provide it.
If I were you, I would request an IEP meeting in writing. Point out the things that are written that you don't agree with, like him counting to 100. Ask why it doesn't state he will have OT or PT when it was discussed and agreed upon. Request for it to be written in. When they tell you some crap about not having an OT, let them know that you know that isn't an excuse and they have 10 days to find one.
Ask why the aid has been pulled and let them you know you don't agree. Address why his grades are falling. If his grades are falling, something isn't right with the services he is getting. That has to be addressed.
Don't stress out so much about this. All of this can be addressed and hopefully cleared up by meeting with the IEP team again and bringing up your concerns and the team coming to an agreement.
About him being labeled DD, they can do that, although I don't agree with it. At age 9, the DD label has to go away. So they will have to address the ASD then, if not before. The problem with the DD label is that he might not receive appropriate autism interventions without that label. Since they won't accept the doc's information, request that the school complete a full educational evaluation, including evals for Autism, Ot, Pt, and speech. Make sure that the evals for Autism are completed by someone trained to evaluate autistic kids. There is a difference in a medical diagnosis of Autism and an educational diagnosis of Autism.
One last thing, request the form of communication you want with the regular ed teacher added into the IEP so that they have to do it.
If you disagree with ANY of the evaluations, you have the right to ask for Independent Educational Evaluations paid for by the District. They HAVE to say yes and pay for the evaluator of your choice OR they HAVE to take you to a hearing (this is the LAW). They cannot simply say no. Once you have outside evaluations, they have to "consider" them in the IEP meeting that will take place once those reports are in. If they reject the opinion of the outside evaluator, you can take THEM to a hearing and most Hearing OFficers will say, "What, you paid for an eval and then rejected it? Come on...this is bunk." And then the H.O. will side with you. ALl of this costs the District TONS of money (you can go to the hearings without a lawyer if your choose or, if you win, the lawyer's fees can be ordered paid by the District, which would be the case in this situation since a no-brainer). Most districts understand the ENORMOUS cost of saying no to an IEE, so they say yes every time to parents who KNOW that request cannot be rejected from a practical standpoint. ALso, if they admit your child needs a service but the therapist has left and they have no other, they MUST provide compensatory services, at your request, once a replacement is found. If it were me, I'd find an outside OT service and request that the District pay to send your child there until such time as they get another OT who can deliver services in school.
I understand yr frustration I have been dealing with this for awhile. Here the kids lose the lable DD at 7 yr old. I have been told even if my son was tested under the ASD that his programming wouldn't change (whatever) but I chose to homeschool my ped recommended outside OT specific to SID stuff I don't think they get that in depth with that in schools but I could be wrong. I do know that it seems most insurence or gov. insurances (at least here in MN) cover most if not all the services for ASD sometimes you need dr forms but if there is a medical dx that is usually not a problem. I hope you get yr son's IEP workied out