question about the actionbuttons

[Tumulten]

You don't need a custom ui, just go F10 -> Interface options -> HUD -> Show Extenden Hotbar check'd

[Kogoro]

Also with the default UI, if you hold ALT it switches you to an alternate action bar, allowing you to customize E,R,T,F,C(if you're a caster),Q,X,V,G and maybe Y or B. Shift commands will not work this way, because you cannot use shift keybinds while holding ALT.