Arrgh, it's like the CK doesn't want me to finish this mod...

Anyways, following spookyfx.com's advice, I tried to edit the "ITMGenericArmorDownSD" sound descriptor, to add a condition.

But the condition box is greyed out! Similarly, most other descriptors are greyed out, except for a few (like the cricket sound descriptor).

Is there anyway I can un-grey them?

Did you check the little box that says "Conditions" right beside the category drop-down under the sound tab?