You should be able to fit everything for a job's rotation on the main Cross Hotbar and Extended. I use the WXHB for actions that are more situational such as healing potions, Limit Break, Tank Stance, Raise, etc.

Also, I would not follow the macro advice above. Jobs can be played comfortably without them - you may just need to rearrange your setup. Macros don't queue, and they really mess with the flow of combat and will often result in a DPS loss. You'll probably also end up mashing buttons even more to get the macros to actually go off, which isn't going to help your hands.