Yes,I own guns,a 9mm Browning semi automatic pistol & a shotgun (side by side) & I have been around guns nearly all my adult life & I bought the Browning for protection back in the mid 1980's.
Would I use them for play?NO!I have seen far to many accidents with weapons over the years.Just by looking at a gun you CANNOT tell it's unloaded.Certain types,like the Walther PP (James Bonds gun but he used the PPK version) have a pin that shows above the hammer if a round is chambered.A few years ago,a young lad tried to rob the local garage with a BBgun,the RUC were waiting & he was shot dead when he pointed the gun at the officer.It was found to be a toy on examining it.
NO .... to all other questions. NEVER. Even a stunt gun that only shoots blanks could kill someone with your scenarios. You could ask Freddie Prinz for confirmation, but you'd have to get him to answer from beyond the grave.
Remember that TV show Bonnie Tyler sung the theme for,"I need a hero" & the actor was playing with a replica gun & killed himself?Most blank fireing guns have a danger area of nearly 50 meters.

Here's a toy bb gun;

http://wb4.indo-work.com/pdimage/02/..._tmm1911a1.jpg
And the real thing;

http://www.enemyforces.com/firearms/colt1911_2.jpg

As you can see,it's very hard to tell which is which.