A. No, clustering within guest OSs doesn't depend on clustering being enabled on the Hyper-V hosts. The requirements for clustering in guest VMs are the same as for physical machines operating in a cluster—suitable network connectivity and, depending on the services, access to shared storage. In the case of guest VMs, shared storage means iSCSI storage.
If you want to be able to move VMs between Hyper-V hosts with no downtime, you need to use Quick Migration or Live Migration technologies, which require clustered Hyper-V hosts.Related Reading: