Based on your reply above :3. and 4. have similar answers to 2 - we don't yet have utilities for this. But for now your basic process would be to restore via the file system, while the node is not running. All state is stored in the blockchain directory.
After the recovery , when the node is started and is in the network as peer , will it sync up any block which is missing in the backup that was just used to recover. if this happens, this will help the node to recover to a point in time.
Thanks