I wrote to you a bit personally but i'll break it down here too — its a first pass at trying to design a ui that cleanly relies on the player & target nameplates for primary information.
the player unit frame is banished to a simple hp readout above the minimap, information elements such as castbar, cooldown tracking and data are mostly arranged around the minimap and revealed through animation when relevant, and action bars are hidden in that collapsable frame at the bottom — appearing on mouseover or when you open your spell book.
the coloured buttons are the micro buttons for various ui panels. I've already moved these out of the collapsing frame and onto the UI since i want to keep that bottom frame focused around the action buttons:
i might give the border around the game some kind of subtle system of colour changes or animations based on status or something, idk