It seems to me that these are very weak:
Point 3 - There is no language organ
While the location and nature of the LAD (Language Acquisition Device) remain little understood or even identified, language is cerebral, so it is contained within one organ, the brain, about which we know very little.
Ponit 4 - There are no language genes
This is only true if number 3 is, which I find questionable. The fact that the human genome has been published does not mean that we have grasped how it all works, especially diachronically.
