They say the UI is the last thing to be finished when developing a game, so hopefully we'll see some major improvements before the game is officially released.
Hopefully, though a lot of things I have issues are, come from D:OS1&2 and both games shipped with similar UI in spite of having similar issues.
I like having spells individually on the hotbar rather than having a general spells button with extra clicking or scrolling.
And feel no desire for some kind of organization? Seperating spells by resource they consume, differenciating main and bonus actions without having to memorize every icon in the game?