I appreciate your taking the time to entertain the thought. Don't you recall Jesus saying "God is able to of these stones raise up children unto Abraham". That one verse answers the whole question. Yes God can make a person from the air that is a son of Abraham therefore a member of the human race. "With God all things are possible". Even passing a camel through the eye of a needle.
Interesting parallel. We are both agreed that God can do what He pleases. No problem there. But it wouldn't have been *fitting* for Him to create Jesus ex nihilo, don't you think? To be a man takes more than just a body plan--it takes being born into the family so to speak. To be part of the spiritual and genetic chain. How do you understand "Son of Man" if not some kind of genetic connection with Adam's race? How do you understand the geneology of Christ? You're kind of making him a humanoid rather than a human--He looks like us, acts like us, but is really something altogether. I'm no theologian but it smacks of Nestorianism.
And then (again) there's the whole difficulty with the "you shall conceive" in the Gospel account. I'm with you on the Virgin Birth because that is a mystery specifically attested by the Gospel. The creation of Jesus' body ex nihilo however, is a presumption on the text and not an explicit teaching, or even a valid inference therefrom. Sure God *can* make Abraham's children out of stones--but *did* He do it in this particular instance? Frankly, I don't see any evidence that He did.