Gun store/show etiquette

I plan on purchasing a new pistol in the next few months, so I am going to be going to gun shows and local gun stores to see what is out there. One thing I have never felt entirely comfortable with is what is/isn't acceptable while handling a firearm in this situation. Obviously, I want to get a feel for the gun in my hand, but I am pretty sure they would frown on me pointing the gun anywhere but the ground.

I know that dry firing is right out of the picture. How about the slide?

What do you guys recommend? I just don't want to go to the store or the gun show looking like a complete tool and offend or upset the owner.

Thanks!!

Tim