Not bad, my only additional comment on top of the pages of comments so far is to pleease, please make the UI fairly navigatable by keyboard commands.
What I mean by that is if I am in combat, I should be able to select a character and at least the high level functions (attack, spell, etc) via quick keyboard commands. Even selecting a spell, then selecting a specific spell, would be great to handle somehow via one hand on the keyboard.
Keyboard commands can be much quicker and efficient than scrolling the mouse all over the screen to select your action; if you can select the action from the keyboard and choose the location to apply that action via mouse, that would be my idea control schema.