Does anyone know what script controls the properties window header? Not just the individual properties within. I want to see if it is possible to add and remove tabs to the properties window, or at the least rename and repurpose those tabs existing. Thank you.
I believe the files you are looking for are not scripts but c files compiled in Blender. If you want to edit them you need to download the source code and search through the c files. You can start at www.blender.org.