How much it matters depends on how your actions and in-actions translate into timed events happening. I am not sure how much of that there is. But I'm not going to say that it doesn't happen.
On my first play, I talked to a character grieving over someone killed in battle, and I chose options that would provoke her to make a certain choice, and she rushed off to do that.
On my current playthrough, I didn't talk to her at all, but after I walked past a certain point, I saw her rushing off to do the same choice, and that was quite interesting.
