I think it is both, first of all emotion can definetly be an obstacle. You tend to follow your emotion which can lead to stress and unwanted feelings or the opposite, but then again this is emotion. Recently from my own experience when I got Tinnitus in the left ear (a ringing noise in the ear) I had trouble ignoring it and it emotionaly affected me. I searched the internet for cures but there are none yet developed, so it started to affect me more emotionaly knowing I might have to live with it and that it can decrease a persons quality of life. I then read an article on a forum saying that Tinnitus is also no more than an emotional obstacle. Imagine being born with Tinnitus, you would not be bothered by it since you are grown up with it and don't even know the meaning of silence. It is because we are used to silence the ringing noise in the ear leads to stress and emotionally making you feel bad because you want to hear silence again. But if you can ignore the emotion you feel towards the ringing noise in the ear you can also ignore the Tinnitus, which gradually may be a cure. Emotions tend to be obstacles because they tend to stop you from doing certain tasks or goals in life, as followed making you lazy to do things and not achieve much. On the otherhand emotion can strongly motivate you and not cause to be an obstacle, although likely there will be times where it does.
Partially emotion can also be a way of knowing but it depends to what extent. If it is a way of knowing then we are talking more about a gut feeling, this feeling leads to knowing whats best in certain circamstances. We then follow that path, but it does not neceserly have to be knowing in an empirical way. Because what is to "know" something, that really depends if it is a fact, and from emotion we cannot always produce pure facts. In the end emotion is who we are and what makes us unique.