I recently created a webpage that will let you configure those three buttons in the raid window of Fetish to do what you want them to do. You could always edit the file yourself but this puts an easier to use interface on the different options you have available.
Check it out here.
All you have to do is pick your class and default CAs/Spells will be filled in for you. You can edit these on the form as you see fit. Once you have them set the way you want them, just hit the button at the bottom of the page. It will generate the contents of the _Fetish_mainhud_raidabilities.xml file for you. Copy this and overwrite the entire contents of that file in your FetishNightfall directory where you installed Fetish and you're done. Very customizable.
As with anything, make sure you make a backup of your _Fetish_mainhud_raidabilities.xml file just in case.
Enjoy!
EDIT: Although this still works, as of FetishNightfall v10.8, you can now just go to the UI/FetishNightFall/Plugins folder and doubleclick on RaidAbilitiesEditor.exe. That will read in your existing _Fetish_mainhud_raidabilities.xml file and let you modify the settings.