The idea that because the FAA does not generally engage in criminal enforcement directly there is not threat of violence would be like arguing that the People's Republic of China is a peaceful country because it does not have an army. (The country does not have an army, but the communist party does)
These are sophistic distinctions which are based partly on fact, but lead to ludicrous conclusions. I should stress that I am not suggesting there should not be an element of force in the enforcement of laws for public safety, but denying they exist is ludicrous.
Perhaps the more interesting question which I will pose in another thread is when does a safety violation necessitate the threat of violence for enforcement purposes.