So, question: What do Helgoland and others believe to be the nature of protest?
Well, we have to separate two cases; I'll assume the existence of a 'we' whose members have common interests, since the goals most people around here are substantially similar. (There's a line about Don Camillo and Peppone wanting the same thing, but disagreeing about the way, to provide a pop cultural example.)
1) A state that is in principle desirable, i.e. one we support in general and only criticize in specific ways
It is in our interest that such a state preserves itself, and that only the aspects we dislike are changed. All we want protests to do in such a state is raise public awareness about an issue, so that it can be rectified: All other forms of action against the state, such as sabotage and protests outside what is necessary for the aforementioned pupose, must be repressed. In practice this means ensuring that the black bloc and other true extremists can be persecuted.
2) A state that is undesirable in principle, i.e. one which we do not support at all
Such a state must be abolished; since we oppose the state itself, we do not care about its laws in any other than the practical sense of them being the rules for the persecution of ourselves. Any form of action aligned with our own goals and beliefs is justifiable.
I firmly believe that the current states in the developed world, even in the US, are of type 1); I know you believe at least the American one to be of type 2), SG, so this is the point where our opinions diverge. All the other differences are merely a consequence of that one.