Why is clicking buttons different from pressing keys? I dont see any difference in them when pvp'ing

You can only use the buttons that are in the window already. Just pick a few perks you want to be visible all the time and move the others down the window. Then make some funky bar from it

Nerf your crazy resolutions ;)

My GUI is just like my setup: there is no 'set' setup, I adept it to the situation. I have about 15 pre-configurated windows and using some backpacks as hotbars. That way I can completely change my setup for raiding, pvm, pvp ect. The pic below shows my pvm lay-out ...