Problems using SyncToy 2.1

Just wanted to clarify three options involved in pushing an RSYNC backup to an NVX from a PC running DeltaCopy over the internet.

Data security is important - if I understand properly SSH will protect observers from being able to make sense of what you are backing up as a packet grabber on the wire would only see encrypted data, correct? It is therefore important to use SSH when backing sensitive data up over the internet?

Using a username and password - is this important? I understand only a user with the proper credentials would have the ability to read or write data to the share on the NVX however if I limit the hosts allowed access to the public facing IP of the DeltaCopy box wouldn't this also prevent anyone not on that network (using the same public facing IP address) from accessing the share?

So, to protect the data from snooping use SSH, protect the data from everyone but the network you want to have access to it use the 'hosts allowed access', and protect the data from others in that same network use a username and password? Am I missing anything?

As an aside I find DeltaCopy > NVX over RSYNC a great solution for backing up friends and relatives data - at least until they get their own NAS and offsite backup worked out.

Thanks in advance,

Bill