Re: Alternative peer-to-peer backup?
The OP did comment about not having to concern themselves with tunnels or NAT traversal. QNAP remote sync definitely requires port forwarding. Unless Synology uses a centralised middle-man thus creating a "removal of service" issue then you'll need port forwarding there too. Not to mention that you also need fixed IP / dynamic dns provision.
Regarding UPS's I'd say you always need one anywhere you have data you value, especially on a RAID array.