This description fits my grandson in many ways. His main diagnosis has been speech and language delays. But he is also taking medication now for ADHD. He did not behave well in school tho he did in day care.
He too was evaluated thru the school by all the people you listed. He was in a therapeutic preschool and entered a special ed program in kindergarten and first grade. He didn't do well in that program and is now in a more specialized school. His class has 6 or less students with a teacher and 2 aides. He continues to get OT, PT, and speech therapy at school.
In addition to that, at the recommendation of the school counselor and his pediatrician he began seeing a developmental pediatrician. His insurance pays for this. This pediatrician is like a case manager. She keeps track of where my grandson is at developmentally and academically. She sees him every 3 months.
After the first appointment she referred him for more in depth evaluations which resulted in more in depth therapy paid for by his private insurance. We did see improvement after those therapies ended. He is still to receive added speech therapy but he refuses to work with the therapist.
He does continue to get all the therapies including speech at school. And, in the last several months is beginning to catch up academically. He's in the third grade by age but still in the latter first and early second grade academically.
We wish that we had gotten him started with private treatment much earlier. The developmental pediatrician is a big help and so has been the extra therapies. She changed his ADHD medication to one that is now working to keep him more calm and focused.
It has been decided that my grandson's inability to do tasks that aren't his preferred task is a combination of his disorder and behavior issues. He's probably somewhere on the autism spectrum scale. He not only refused to do anything in which he wasn't interested but he also was disruptive of the whole class and acted out in anger.
He's now 8 and is able to participate in class in a more consistent way. He is now well behaved in school and at home most of the time. I think his medication has been a help there but I also think that the consistent and firm discipline that his teacher and aides are able to provide in the small classroom is just as much a reason for success.
Early on in the program, when he was nearly 3, a social worker came to their home and taught his mother how to manage his behavior in a more effective way. Discipline is quite simple. There are just a few rules such as show respect which includes no hitting and do as you're told. When he doesn't follow the rules he's immediately sent to his room, not as a traditional time out, but as a way for him to regroup and start over. He can play, watch TV, listen to music, etc. When he's able to come out and say he's sorry and then do what he was told to do he can come out. Mom gives him a hug, repeats the lesson, and life begins over.
It did take a couple, three weeks, before he'd go to his room without assistance. Now, there are times he puts himself in his room.
I suggest that some of your son's behavior is due to his age and immaturity. Many 3 yos are still playing more parallel than together. Wanting to have his friends around only some of the time sounds normal to me. He could be an introvert whose basic personality is such that he likes his own company and doesn't need as much social interaction as us who are more extroverted.
I would recommend getting him in to see a developmental pediatrician and listen to her/his advice. They are trained in evaluation and treatment of the child who is different than the average child.
His not responding to conversation could be a part of his language delay and/or immaturity. This could also be an indication that he's somewhere on the autism spectrum scale. My grandson just began to have somewhat coherent conversations with us around 7.
In regards to having him do a not preferred activity before doing a preferred activity, this is usual in the therapeutic setting. He provides an incentive to do what the child doesn't want to do. With my grandson they eventually learned to do it the opposite way. He frequently is allowed to do the preferred activity with the promise that he'll do the not preferred one after that. This seems to work better.
What has been most helpful in providing treatment for my grandson is for the therapist/teacher/aide to be flexible enough to try different ways of approaching him. Yes, these children have much in common but are more sensitive to how things are done than the average child. They are not naturally compliant. They do march to a different drummer in many ways. It seems to me that their brain is wired differently in many ways.
My grandson has difficulty speaking and with using language because his brain doesn't get messages that help him do so. He needs lots of firm touches. Holding him frequently helps him calm down, even as he fights it, while in comparison his sister does not respond to holding when she's angry.
Have you asked the OT for suggestions on potty training? He is still young. Many children, especially boys train later than 3. But if he's physically mature and ready for training there may be ways to help him along.