You should be able to see files syncing between your device and your Murena cloud account. For ex a document on the device should show up in your cloud after a few minutes. It should work the other way round as well. I just checked on my device and account.
Once we enable the MurenaRecovery folder there should be no automatic deletion unless you manually delete a document in either location.
Third party apps are disabled for now as we are not sure about their behavior and they could end up updating or deleting existing files.
Also we will update when the MurenaRecovery folder will be enabled.