in game press ESC , select preferences, then select User interface
a section will come up that says Quickbars
if you tick enable left and enable right quickslot and then apply
you should get extra bars come up at both edges of your screen
i put the attacks i use more for close combat and pve on one side and the buffs and heals etc on the other side
and keep my main and most used attacks in the center
hope that helps
i have all the quick bars up,im just running out of keys,right now im using stuff like page up,in the next few levels ill run out of keys there...