For your questions:
- What kind of folders is DFS designed to replicate?
DFS Replication enables you to replicate folders between multiple servers.
If you want to keep folders synchronized between servers, you can create a replication group for them. Then the content between the folders will keep sync.
- Is DFS meant to be a backup?
DFS Replication is not a replacement for backups. If a file gets deleted, changed, or corrupted on one target server, it will most likely be deleted, changed, or corrupted on the other target servers. Therefore, you still need to use backups to provide data protection and recovery.
- No. As said, that's why a backup is needed.
More information for your reference:
DFS Replication: Frequently Asked Questions (FAQ) Best Regards,