No
No
No
Why not ask Walther instead of us? Waltheramerica.com
$250-$350
Cost, caliber and maker.
No
Some people use a Walther P22 for shooting practice purposes, some use just for a day at the shooting range. The Walther P22 is known for being fun to shoot and no recoil. Some use as a gun to protect their family.
Earl's Repair Service, Walther's USA site.
Walther uses a date code of two letters.
Nope- not possible. The P22 is a blowback operated action, and is suitable only for a low powered rimfire cartridge. A .45 requires some form of a locked breech, which the P22 does not have.
Stick with the factory offering.