Someone insulting you on the basis of studying martial arts
To be honest, I usually laugh at their insults / jokes at my expense.
Confronted by an unarmed thief who is physically abusive
Not since 1st grade have I had someone try to take my lunch money. i.e. This was the last time I was in a physical situation with an unarmed person.
Confronted by an angry drunk at the bar
I usually laugh. I then smile. If they are far enough away not to touch, I state in a real loud clear voice, "Becareful, or I will stand up and you will knowck my *** out, and I will fall to the ground and break your ankle." This lets others in the area know I do not want to fight and I am not threatening them. Most of the time the loud one and his friends just laugh. The sober ones or smart ones realize that the statement of breaking their ankle by accident, is something to think about, as it is possible. This gets them thinking about the pain and the hospital time.
I have also asked if they have good insurance. I tell them I have good insurance. I ask if they have their card on them, for when they go to the hospital. But this is usually done when there is already that beginning physical contact.
Confronted by an armed thief, punk...whatever
Armed. Knife at a distance, I pull my belt off and use it as a range weapon. Knife up close, I try to create room. Or if it was just an attack, I try to react. I am not 100% in reacting in time. Note: none of these were for a thief, it was just assault.
Firearm. I reach for my wallet and drop it and step back slowly.
I opened the cash register and walked away wiping the counter down trying to create room. i.e. get back into the back and behind the cast iron pizza oven. The guys was not trying to rob the place. He pulled it out of a pocket looking for change. He came back later and apologized. It helped that he came with an officer.
That's it. What would you do? Add more situations if you want.
I did modify the theft to assault. For some reason people do not seem to want to rob me.