I would stop watching the show all together if the writers killed off Katherine. She's the only reason why I watch TVD.

Hmm. To be honest, I don't know if the Augustine Vampire experiment is the key to saving Katherine... (but obviously, I could be wrong). I think Nadia might be the key to saving Katherine, in her actual life and also her soul. I think once Nadia finds out Katherine's situation, Nadia will find whatever means necessary to save her mother.