Hyper-V back-up questions
1) The same rules will be applied here as with an image-based backup.
You need to schedule full backups to make sure purging is performed correctly
These settings will work fine, but note that if you de-select any VM from the plan that data becomes "orphaned" and will stay on storage side, so it's better to plan beforehand and make sure you select only those VMs that you want to back up.
2) The software will always back up the current state of your VMs no matter what snapshot you decide to restore.
3) You can ignore those messages. If your backups are successful then everything should be fine here.
As an additional suggestion I can provide this link with permissions required to properly perform backups using our software:
https://kb.cloudberrylab.com/kb1078/