Re: I need some outside perspective
Have you seen a geneticist? After the second child was diagnosed your ped should have referred you to one. Autism definitely has a genetic component and can run in some families. If you are planning on having any more children a genetic consult is something you definitely need to do although honestly I would pursue it either way just so you can get a better picture of your children's future.
I'm not sure about the developmental aspect. It has been a long time since I had a baby and my only child has severe global developmental delays from infancy onward.