Rainman, if you can't help it or be out of a job then that sux, maybe u should find a new line of work. Some druken moron can jab a small knife into you just as easily as suckerpunch you from that range.
If i really wanted to hurt someone who really didnt want to fight me, all i'd have to do was get right up in his face, inches away with my arms out wide while talking shit and shouting. Then i could bring an arm in from the side at the edges of his vision for a square hit on the nose. If you've ever had a broken nose(or even a hard hit) you know how much that can daze/disorient you. That'd be enough for me to take him to the ground, sit on his chest, and go to work on his face. Before i got pulled off i could do some serious damage.
All I'm saying is the first punch often wins a fight, so you gotta make sure it's not a suckerpunch u didn't see coming. Don't let threatening people in arm's reach. Ever.