What does "exhibit" mean? If you flip your jacket back to reveal your IWB holster at 3 o'clock and hold your hand near the grips, Are you "exhibiting" your firearm? I'm not sure, but you're probably going to scare a bunch of people. Be prepared for that.
Dan
It depends on your state's laws. In Arizona, open carry is legal, and they don't say where you should keep your hands. Some other states aren't so tollerant of open carry, and it can get you arrested pretty quick.
As far as the OP's question about pulling your firearm, that's where you need to know the state laws too.
Arizona has certain stipulations for using deadly physical force, and it's pretty much the same for pulling your firearm. The law states something like "if a reasonable person would be in fear of their life or serious bodily injury, or the life of another, or serious bodily injury to another...".
But, Arizona also allows the use of physical and/or deadly physical force to the extent necessary to stop certain serious felonies in progress. Among those are arson of an occupied structure, murder, kidnapping, rape, child molestation, aggravated assault, first degree burglary, and others.
Know the laws of the state you're carrying in.
Daryl