I'm not sure about the licensing requirements, you need to get in touch with the Cisco Account Team for that. Howeverthe upgrade is pretty straightforward. Just check the release notes for any caveats.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...