Your neighbor is not a good resource for this. It doesn't sound like ASD to me, not even a little. To me, it just sounds like you have a fussy kid. As a previously fussy kid who has met and raised a couple like me, it is just...what it is. I think a "time will tell" approach might be best. If the speech issues clear up quickly, then that's a sign. If they don't, that's a sign. If he gets more OCD about things, that's a sign. If he becomes more accepting, that's a sign. Right now, you have a couple of quirks that do register, but without them hindering his day-to-day existence they seem more quirk than disorder to me.

If anything (and I know I am being an asshole suggesting this) I think you might have a gifted kid who is above the curve and just developmentally growing into his own brain. He's going to be blowing the doors off the math barn in a few months. I think you're going to see some exceptional behavior, mixed with some social drawbacks that need correcting. That's just a guess, but that's my best two cents.