I'd like to add something: Tactically speaking, delayed actions would be even more interesting here than in a D&D-like game. When you use delayed actions in D&D, basically, you set a trigger for a certain action during your turn (e.g. "when the enemy X casts a spell"), if this particular condition occurs before the current round ends, you can interrupt the enemy during his turn, otherwise you've wasted a precious action.
Basically it's a bet. Considering that in Original Sin you can save action points for the next round, it would be an even more interest bet. Will you save your action points for the next round or will you use them for a delayed action in the current round?
