I've very rarely felt myself to be in much danger at work.
A. As Medic Tim mentioned, we stage most/all of the time for crime scenes until PD has arrived and "cleared" it.
B. Most people, apart from drunks or the mentally ill, don't aim to hurt medical providers.
C. Verbal judo defuses ~90% of potential conflicts
D. When we get in to the rare "tussle" with a patient because we have to, we outnumber them, have restraints, chemical sedation, and radios so we will soon outnumber them even more dramatically.
E. Situational awareness can keep you out of a lot of troubling situations. Know what's going on around you, and plan what you'd need to do before it gets to that point.