Sounds like a good idea to me. The world I live in if I'm approached by someone in a parking lot, sidewalk, alley, etc. I tell them to leave me alone. They don't do it. I speak louder. They still keep coming, the CCW comes out. The flashlight gives you a great buffer between speaking louder and pulling a lethal weapon out. It does all of the following:
1. Gets their attention.
2. Blinds them.
3. Their night vision is shot so even after you turn off the light they can't see as well as you can.
4. It confuses them.
5. If it's bright enough it hides your movements so if he keeps coming he doesn't see you draw your weapon. Depending on the scenario this can be good or it can be bad.
Yes it will probably anger all of them. Only a very small percentage of these types will act more aggressively from it. The most important thing it does is draw attention to the BG. That's something they don't want at all and will most likely cause them to re-think their actions.
A hit with a .45 ACP beats a hit with a .22 LR everytime. A hit with a .22 LR beats a miss with a .50 BMG everytime.