If you apply for exemption from the regulations, you have to state from what sections you are seeking exemption. It seems to me that you got exemption for most stuff but the items of concern were listed and had to be addressed. The agricultural part seems to have been for the rezoning which is evaluated by the department of agriculture. I also preume that you are going to run the development as a business venture, hence the rezoning. If you paid that much, then maybe I am in the wrong business

If any development took place or was started before the impact management regulations were gazetted, need no further action. If the development started after the regulations without the necessary ROD, then you have to apply to rectify the unlawful commencement in terms of section 24 G of NEMA. Therefor not "all" the airfields will be affected.
Regards
Stan