Combat overall is strategic. My understanding is it's similar to KOTOR, where once you click on an enemy, your character will continue to attack them as fast as they can unless you switch targets, the enemy dies, you fall unconscious, or you change tactics. So not a whole of clicking at all.
If you want to use a special ability, special attack, or spell, you'll need to select that. Some special attacks, particularly melee ones, and certain abilities (like the bard abilities) just need to be triggered and then work passively until you deselect them or you run out of stamina. Others need to be triggered each time (many archery talents and spells).
Also, remember you control your whole party potentially. You can just have them go on autopilot, or you can "shift focus" to a companion for awhile and let your main character be controlled by the computer. I'd highly recommend doing this if you're playing a warrior while you have a spellcaster in the party, for example - spellcasters generally need a lot more active control.
Also, the game allows you to set up AI scripts (like if your HP goes under X amount, use a potion, etc). Each character gets one script per level, IIRC, and you can use skill points in combat tactics to unlock additional ones. So you can make the AI of your party better with time.