Re: is this sign of autism
Sounds pretty classic, textbook autism to me. Not responding to his name, pulling you around instead of pointing to things, toe walking (not as big as an indicator- kids usually outgrow this by 3 years old, but since your son has 2 very big red flags already, I would say that's a red flag, too)- these are all signs of autism. I mean very big red flags, they almost never indicate something else, they almost always mean autism. Hand flapping and any other repetative behaviors are some signs, as well.
You are very lucky to have figured out that something was wrong before your son is, say, about to start kindergarten. Now you can start thinking about what kind of treatments you want to start. I would suggest you talk to a developmental pediatrician, and try to go ahead and get a diagnosis, so that when you start looking for services, you have all your paperwork lined up. I would also suggest you start reading everything you can about autism and the available treatments, especially something called Applied Behavioral Analysis, which is the therapy with the most studies done on it and has been proven to be very effective. I think this early in the game you have so much opportunity to get your child the help he needs, and he can be very happy and healthy, okay? So no time to panic. But I think you really need to talk to a professional with experience with children with autism.