I think this video does not provide good examples for progressing in freestyle, his style is simply not balanced and streamlined enough to serve as a role model.
Anyhow, if you stand straight (on land) and are able to turn your head 50-60 degrees to either side then you are able to do core balance drill or skating drill (or swim freestyle) and look straight down while your body rotates from side to side. If you are unable to rotate your head on land you will not be able to rotate your body in the water and look straight down. That's basically all to it.
If your are physically able to turn your head to the side then you should look straight down while drilling or while swimming. If you always rotate your head with your body it is quite difficult to swim straight and keep a balanced position.
If that was your question. Otherwise I didn't get the point.
Hang on in there...