The "delete other formats when updating" and "Automatically Convert new/updated ebooks" options are what you want.
I don't see the errors mentioned with my Voyage, but then I don't do anything with 'connection to cloud' on it.
I've found the Kindle Voyage to be much more rugged than the Nooks I used. I had several Nooks develop screen cracks/stars and other failures while my Voyage is going strong under the same 'drop it once every couple weeks' regiment.
