I think I get it.Well, you could modify the save loading routines (yuck), or add default statements for these variables.
The default statement will create the variable on save or load if it doesn't already exist. If it exists, the default statement does nothing.
So a fix for older saves would be that instead of using init and then define every variable after that again, it should just say
default annefaith = True for an example.
If that's the case then a fix for older saves, that do not want any kind of mods, should look something like this.