What are the Standard Controls for Headphones on Stock Android Kitkat?
is there a standard reference for what the different tap patterns are supposed to do?


Basically, what you have noted is how most BT headphones function with their buttons. 


is there a way to program the controls to achieve a consistent interface across applications?


No, since each app maker decides whether or how to implant/interpret BT controls. It can be quite annoying when playing from different apps and the pause button does not work.


do all headphone manufacturers implement basically the same headphone controls, so that apps for manipulating one brand will work for other brands?


From my experience, owning several BT headphones, the buttons are always the same, but the placement is not. I tried finding a BT standard in hopes to find if the buttons are standardized, but I was not able to make any grounds.