Any way that you attack a groups looks, way of life, way of thinking and way of believing is terrorism. To claim that a group who leaves those questions up to the individual as muslims do when it comes to changing to islam or not to me is just making excuses.
The fact remains that the more the conflict can be observed I would say a group that will move in, start war, then instill there way on two entire different countries is far more aggressive dangerous and deserving of fearing than a group who let people decide what it is that they believe and what they do not.