Hi.
I don’t think so. If you encrypted file is corrupt, you can’t decrypt it anymore. Cryptomator does only encrypt. It does not add restore information like Windsor packages.
If the masterkey is corrupted, you’ll find a backup next to it. Cryptomator does create this backup file after a successful login. And there is a way to create a new masterkey as long as you have your vault recovery key available. Recover masterkey file with recovery key? - #4 by tobihagemann
If the vault is corrupted, see above.
Exactly. It’s like with any other file. Regardless if it’s encrypted or not. It needs a backup.
Cryptomator covers privacy issues with online stored files. It does not cover data security issues. This is the job of you backup strategy.