Hm, I would agree on the 2nd part @Lemaniaque - To have some kind of option to relegate or even kick-out an F.A. captain if the members believe that he/she is inactive. Right now our support agents can help out with such cases but only if the captain has been absent for 30 days.

I don't see what is wrong with the F.A. controls though (Interface). I mean if you're the captain, you simply have to go to My Association > Overview > Members > Select the "..." button on any of the profiles and chose Promote button after that. There is even a confirmation request from the game.
Example:
Click image for larger version.  Name: How to promote to F.A. Capatain.jpg  Views: 29  Size: 42.1 KB  ID: 74663

But anyway, we all make mistakes every now and then.