I believe we're thinking way too much into this. I really doubt the Naruto universe follows the real world rules of DNA structure and all that.

If you're born into a bloodline family, you'll get the abilities. Naruto isn't part of a bloodline, so none of his kids (if he ever has any) will get any extra abilities. Naruto has extra abilities because there's a demon inside him, but any kids that he has won't have that demon, so therefore no extra abilities. The End.