Can learning shotacon karate be an alternative to owning a firearm for self-defense?

Self Defense is a legal term. You need to be able to prove self defense applies if you choose to fight whether it is with a weapon or not. You are generally either fighting or avoiding a fight in a self defense scenario. You will never be as effective without a firearm as with one, however having one is also a major responsibility and if you do have a firearm you should still dedicate a lot of time to training with it.

Nope ............

I guess every little bet helps your chances .