Maybe this can be the answers:
1) There is a configuration on cloud manager in Manage Account page where you can disable the use of Saas Platform. When disabled you can only operate connecting directly to the connector ( through your intranet ).
2) No, you can also operate with CLI and System Manager directly with the Ontap cluster. Cloud Manager is good for adding o removing disks and aggregates because it manages all the commands with you cloud provider.
3) Yes, it's like any other Netapp
4) I'm not sure but, in case of a share, I think you can utilize the feature of Previous versions directly on the client.