With the exception of the face picking, you have just described my eldest son at aged 2.5 years. He is tall for his age, so people would ask him about kinder and he would just look blank and I was forced to explain that he was only 2 and completely non verbal. I was criticised for his behaviour, lack of eye contact, lack of toilet training, etc, over and over from all the well meaning strangers who felt it was their business. He said lots of words once, then never again. There was nothing he could say regularly, we used sign language for food, drink, etc, because he would just tantrum and get frustrated otherwise.

Long story short I took him to a chiropractors about his knees (he was knock kneed) and she adjusted something at the back of his neck. He started talking about ten minutes later, and was massively improved in every aspect of his behaviour within a few weeks. He is still a whithdrawn, serious boy, and he still needed some speech therapy. But chiro really helped him. Have you tried it, and if not would you be willing to? I was very sceptical when my chiropractor said she could help, but she explained it as all the knowledge was just sitting in his brain (all the words he had said once) but the information was getting blocked when it was trying to leave his brain, so my fixing his neck (vertebrae out of place which was causing a disruption in the flow of information) she basically removed the blockage and the words all came flowing. Once he could speak the rest of his behaviour calmed down or was easier dealt with because we understood one another.