Being an Indian, emotionally I am also not in favor of Aryan invasion however As I do not have much knowledge hence I do not talk about it. Some day I will acquire enough knowledge and see myself if my beliefs are correct.
Now to your specific clarification, the term 'Dravidian' is used in the inscription and it is not from the editor's whims and fancies. It is our kings who have used it, which suggests that this term in use in old times. You can check yourself in Epigraphia Indica vol XII, the inscription text clearly states 'Dravida-desa'.
I too agree with you on "Aryan Invasion Theory itself has been debunked and proven to be just a theory".
The word Dravida is used in texts and inscriptions for denoting the southern area and language but not any race. The national Anthe itselfsays Dravida, Utkala Banga.
The entire Tamil, Andhra,Karnataka and Maharshtra people are known as Pancha Dravidas. Oriya, Bengal, Gujarat, Malawa and UP/Bihar peopleas Pancha Gaudas.
The word is used in many contexts but defenetly not on race.
Adisankara himself mentins Dravida Shisu. Some say it refers to Sambandar and some say he refers himself as dravida sishu.
Some of the southerners who moved to North have the surname Dravid. ( Rahul Dravid).