Most modern semi-autos have a firing pin safety that prevents the gun from firing unless the trigger is pulled. That is, you could drop a gun and it would not go off. Some guns also have a manual safety that you would (usually) push downward to turn off prior to firing. Some guns also have a grip safety -- where you would need to be holding the grip the proper way in order for the trigger to be able to be pulled.
For no nonsense protection, it is hard to beat a revolver. Mind you, you probably would not like the recoil of a very light J-frame revolver (from Smith & Wesson). But a Smith & Wesson Model 36 (Chiefs Special) would be heavy enough to eliminate much of the harsh recoil from firing off a round. Ruger and Charter Arms also make similar models. Then, you could load the gun with Federal Hydra-Shock 110gr JHP that is designed for low recoil, and you would be fine.
With a semi-auto, I think you would need some regular time at the range to stay proficient with the weapon. With a revolver, once you have practiced enough to know what it will do, you would probably not have to have the regular range time. These revolvers are pretty much just point and pull the trigger -- not worrying about a safety, magazines, etc. However, practice still is important for any weapon.
Just some things for you to consider.