Yes, yes, yes and no. See I think we can draw a line between understanding emotions and using emotions to arrive to some conclusion. Our ability to conceive emotions, in addition to feeling them, is what helps us imagine ourselves in other people's shoes. Ie, empathy. So, I propose, let's first experience an emotion, and then, after trying to isolate and examine that emotion, let's make a decision which is detached (as much as possible) from said emotion, but still taking it into account.
Eg. 'Wow, these protesters sure make me mad, I want to punch them in the face.' Stop. Why did I feel mad? Am I insecure? Should I be? Is violence the best course of actions? So I recognize I'm mad, but I might not be justified in being mad and won't decide on resorting to violence because of my emotion. My being mad gives me no leverage in making a rational decision. But it's a fact that I concede and consider. So I either may go and strike a conversation with a protester, or, further taking into account my emotion, ignore them and walk away.