Of course the P38 can be shot! While there are documented cases of slide cracking, especially with well worn examples, it is not common...nor is the pistol made of glass. Use appropriate 9mm ammo do a careful inspection of the parts prior to firing and maintain a clean, well lubricated pistol.
I regularly fire my 1945 era P38 and sometimes remove the original barrel/slide and use a modern P1 slide/barrel. An inexpensive means to enjoy the gun without fretting over damage to a war relic.
The P38 is a battle-tested weapon, not a fragile toy...I hardly think you will encounter any sudden problems with occasional use.
I regularly fire my 1945 era P38 and sometimes remove the original barrel/slide and use a modern P1 slide/barrel. An inexpensive means to enjoy the gun without fretting over damage to a war relic.
The P38 is a battle-tested weapon, not a fragile toy...I hardly think you will encounter any sudden problems with occasional use.