Here is my main DPS/Tank UI. https://imgur.com/a/89tVK
Since it it my main I have 3 mount that I like on quickbar (but mostly I'm using random mount). Markers for ops. Binoculars and seeker droid (probably should remove them), PET which I nere used since I putted him there, FOUR recovering items, 4 legacy utility droids FOUR teleports. And I still have 3 free spots. Just nothing to fill them.
When I use that layout on alts, I usually turn off 1-2 quickbars, since there is nothing to put there.
And here is my Healer interface, which I LOVE: https://imgur.com/a/SJPOk